Paranormal Crime Investigations: Brotherhood of the Crescent Snake Walkthrough

Welcome to the Paranormal Crime Investigations: Brotherhood of the Crescent Snake Walkthrough! Use your Paranormal Crime Investigation skills to solve a string of bizarre murders plaguing the city of New Orleans! Whether you use this document as a reference when things get difficult or as a road map to get you from beginning to end, we’re pretty sure you’ll find what you’re looking for here. This document contains a complete Paranormal Crime Investigations: Brotherhood of the Crescent Snake game walkthrough featuring annotated screenshots from actual gameplay! We hope you find this information useful as you play your way through the game. Use the walkthrough menu below to quickly jump to whatever stage of the game you need help with. Remember to visit the Big Fish Games Forums if you find you need more help. Have fun! This walkthrough was created by BrownEyedTigre, and is protected under US Copyright laws. Any unauthorized use, including re-publication in whole or in part, without permission, is strictly prohibited.

General Tips

Paranormal Crime Investigations: Brotherhood of the Crescent Snake

Click on Settings (A) for Sound, Music, Full Screen and Custom Cursor settings.
Click on Extras (B) to replay the mini games you have unlocked.
There is an optional tutorial after the introduction to the game.
Move your cursor around each scene to find interactive areas by watching the cursor change.
The cursor will change to a magnifying glass when you can look closer at something.
To exit a close-up box, click on the x in the corner or click anywhere outside the box.
The cursor will change to a hand when you can interact with something.
The cursor will change to a talk bubble when you can speak to someone.
The cursor will change to a question mark if you can learn more about something.
When you get a glowing item in inventory, it needs to be moved to your PCI Field Kit in the lower right of the screen to be analyzed.
Hints are available in the lower left for both the Hidden Object Scenes and the regular gameplay.

When the PCI Field Kit (C) glows you have updated case files in your PCI Digital Case Log and Database.
Scroll through the data files by using the arrows (D) on the right.
You can switch between a Map (E) and the Log (F) by clicking on the bottom right of the PCI Kit monitor.
Hidden Object Scenes will be marked with sparkles.
Hints replenish in 30 seconds.
Interactive areas are marked with a glint.
The items listed in green in a Hidden Object Scene find list requires an extra step to find; these items will be marked in the same color on the screenshots.
Items that can be combined will automatically pop up with a box showing you the combination once you have collected all the pieces.
The game is not fully linear and certain actions in one area trigger Hidden Object Scenes in another.
If there is a Hidden Object Scene available in the guide that you do not have, please explore other areas and come back or check the guide for what you may have missed.
Puzzles can be skipped after a short wait.
There is a brief fog on the Hidden Object Scenes if you randomly click.

Chapter 1 - The Brotherhood

Look close at the body (G) and click on the sheet.
Click on his back pocket (H) to see his student I.D. Card.
Take the IRON STAR (I).
Click on the symbols on the ground on the upper left of the close-up.
Click on the symbols (J) etched in the victims arm to get a SAMPLE ANALYSIS: STRANGE MARKINGS.
Place the SAMPLE ANALYSIS: STRANGE MARKINGS in the PCI Field Kit to analyze it.

The object is to catch the substances floating around (K) that match the highlighted substances on the left.
When the next substance is to be found they will enlarge and flash briefly on the screen to let you know the substance you are searching for has changed.
When complete you will get an analysis of the sample; click on the analysis to continue.
Click on Madame Oracleaux on the left.
Look close at the table on the left to access a Hidden Object Scene.

Move the menu (in red) to get the INSULATED GLOVES.
Find the objects listed.
Head down the street to the right.
Click on the crows and note you need to scare them away.
Click on the scarecrow on the left and note that it is missing parts.
Click on the table on the left to access a Hidden Object Scene.

Click on the crow (in red) to get the bloody feather.
Find the items listed and get an AXE.
Back out of the area and head left.

Look close at the newspaper (L).
Look close at the box (M) and click to remove the lid; note we need a special tool.
Head down the left street and click on the opened gate entrance.
Take the SHOVEL HANDLE (N) on the right.
Look close at the glowing symbol (O) on the ground and click on it.
Look close at the lock on the gate (P).
Click on the area to the left of the gate to access a Hidden Object Scene.

Find the items listed and get a RAGGED SHIRT.
Back out one time and head down the street on the right.

Look close at the paper (Q) on the ground on the left two times.
Click on the electrical box (R) on the left.
Use the AXE on the chains on the electrical box.
Look close at the electrical box.
Using the chart (S) on the inside of the door panel as your guide, connect the wires on the right.
Use the INSULATED GLOVES to move the wires.
Hint; Start with A and D since the solution for those are given on the panel.
Solution; A=1, B=3, C=5, D=2, E=7, F=6, G=8, H=4. See screenshot for solution.
Click on the sewer grate (T) to access a Hidden Object Scene.

Open the flap on the popcorn box (in red) and take the fishing lure.
Find the items listed and get a WREATH.
Go forward one time.

Look close at the memorial (U).
Place the WREATH on the left hook (V).
Note the missing pendant (W) and click on the newspaper (X) on the upper shelf.
Look close at the glowing symbol (Y) on the ground and click on it.
Click on the barrier (Z) on the right.
Head down the street on the left.

Take the PIPE (A) from the wind chime.
Click on the barrier on the left.
Speak to Madame Oracleaux and enter her shop.
Speak to the Madame Oracleaux again inside the shop.
Take the PENDANT (B).
Back out of the area two times.
Look close at the memorial and place the PENDANT in her hands.
Head into the open gate to the cemetery on the right.

Attempt to head straight down the path.
Take the SCARECROW HEAD (C).
Look close at the statue pedestal (D) on the right.

The goal is to remove all the items to reveal the circle of protection by removing the top ones first. See screenshot for one solution.
Get a SAMPLE ANALYSIS: WHITE PIGMENT.
Place the SAMPLE ANALYSIS: WHITE PIGMENT on the PCI Field Kit to analyze it.

The goal is to match the particles on the left with the ones on the right.
You need to match exact shapes, not just the colors and type.
When complete, click on the lower left gravestone to access a Hidden Object Scene.

Touch the rose (in red) to get the ROSE PETALS.
Find the items listed.
Back out of the area one time and head left and then into the shop.

Take the EYE OF NEWT (E).
Back out of the store and Madame Oracleaux will give you a TALISMAN to see dark magic that will reside on the left of your inventory bar.
Note the magic circle on the barrier on the left.
Back out of the area two times.
Click on the sewer grate on the right to access a Hidden Object Scene.

Find the items listed.
Get a piece of CHALK added to your inventory.
Back out of the area and head right to the Café du Globe.
Click on the table to access a Hidden Object Scene.

Find the items listed.
Get a TULIP added to your inventory.
You should now have all the ingredients (TULIP, CHALK, EYE OF NEWT and ROSE PETALS) needed to make the white pigment.
Click on Combine when the box automatically comes up to get the MIX SUBSTANCE: WHITE PIGMENT.
Place the MIX SUBSTANCE: WHITE PIGMENT in the PCI Field Kit.

The goal is to clear the board by matching all of one color together to eliminate them in the number of moves listed in the upper left.
You can move the samples by clicking on any two touching substances to switch them or by clicking on the left or right arrow to rotate the screen 90 degrees.
Any three of a kind touching each other will automatically clear off the board, so be sure they do not touch until all of one color can be combined.
The solution is; click the left arrow one time and then click the right (or left) arrow.
Get a WHITE PIGMENT when complete.
Head to the right one time.

Place the SCARECROW HEAD and the RAGGED SHIRT on the scarecrow (F).
Take the SHOVEL SPADE (G) and automatically combine the SHOVEL HANDLE with the SHOVEL SPADE to get a SHOVEL.
Back out and head left one time.
Go forward down the right street three times into the cemetery.
Look close at the circle of protection on the statue base to the right.

Place the WHITE PIGMENT in the bowl (H) on the right.
The goal is to complete the diagram by tracing the red dots on the circle.
Click on the white pigment to pick it up. You will not need to get more unless you make a mistake.
Draw the lines by starting at one end of a line of red dots and click-hold the mouse and trace to the end. Release the mouse and click-hold and trace the next trail of red dots.
Repeat until all red dots are gone.
Back out of the area, head left and then right into Madame Oracleaux's shop.

Speak to Madame Oracleaux and she asks for a shovel.
Give the SHOVEL to Madame Oracleaux and take the RED CANDLE (I).
Back out of the screen four times and head right two times.
Click on the table to the left to access a Hidden Object Scene.

Find the items listed.
Get a BLUE CANDLE added to your inventory.
Back out, head left and head straight three times to the cemetery.

Place the BLUE CANDLE on the left (J) and the RED CANDLE on the right (K).
Click on the crypt door on the right.

The goal is to slide the tiles to complete the picture (L). See screenshot for solution; click on the spaces in the order listed.
Enter the opened crypt.

Look close at the altar (M) in the back of the room.
Take the 3 NUMBERED STONES (N) and the second IRON STAR (O).
Look close at the plaques (P) on the floor and click on each one individually.
Take the 4th NUMBERED STONE (Q).
Place the NUMBERED STONE II on the bottom center of the left plaque (R).
Place the NUMBERED STONE IV on the bottom center of the 2nd to the left plaque (S).
Place the NUMBERED STONE VI on the bottom center of the second to the right plaque (T).
Place the NUMBERED STONE IX on the bottom center of the right plaque (U).

Move your cursor/beam of light to the purple emblem (V) on the bottom middle and click on it.
Click on the glowing symbol (W) in front of you.
Exit out of the grave and speak to Madame Oracleaux.

Chapter 2 - The Iron Stars

Take the BLUE EGGPLANT (X).
Take the PIPE (Y) from the wind chime.
Head straight one time into the bayou.

Take the SCRAPER (S).
Use the SCRAPER on the bottom of the boat (Z) until gone and click to turn over boat.
Wind the winch (A) until it will not go anymore and then click on the lake house (B) on the far right to move forward.

Take the BATTERY (C).
Look close at the bulletin board (D) and read the moss solvent list and the chemical X ingredients.
Take the BLUE BEETLE (E).
Click on the cut-out center of the deck.
Look close at the frayed rope (F).

The goal is to connect the frayed rope ends on the left to their matching frayed rope ends on the right.
Match the ropes by clicking on one end, then follow the chalk line to the other end and click on it. See screenshot for solution.
Back out of the area one time.

Click on the winch (G) and head back to the lake house on the right.
Click on the body and take the BOLT CUTTER (H) from his hand.
Click on the body again and note there is something under the moss.
Get a DATABASE ID SCAN: FINGERPRINT automatically in your Inventory.
Place the DATABASE ID SCAN: FINGERPRINT on the PCI Field Kit to get the identity of the body.
Look at your PCI Field Kit Log to see the ingredient list for the moss solvent.
Back out one time and speak to Madame Oracleaux.
Head to the boat house on the upper left.

Use the BOLT CUTTERS on the chain link (I) covering the wheel until the wheel is exposed.
Turn the wheel to open the boat house gate.
Click on the right wall of the boat house to access a Hidden Object Scene.

Click on the center flytrap (in red) and take the bee.
Find the items listed and get a ZOOPLANKTON PETRI DISH.
Head forward one time to the crane.

Look at the hopscotch board (J) and note the 3 numbers; 652.
Look close at the crane cabin (K).
Note the missing button on the dashboard.
Take the LIGHTER FLUID (L).
You should now have all the ingredients for Chemical X (LIGHTER FLUID, BATTERY and ZOOPLANKTON PETRI DISH) and you will automatically combine them to get MIX SUBSTANCE: CHEMICAL X.
Take the HOOK (M) on the dash and exit the cabin.
Use the HOOK on the fire escape ladder (N) and click on the door on the upper level to go up.
Use the code from the hopscotch board (652) to open the lock. See screenshot for solution (O).
Place the MIX SUBSTANCE: CHEMICAL X in the PCI Field Kit.

The object is to catch the substances floating around that match the highlighted substances on the left.
When the next substance is to be found they will enlarge and flash briefly on the screen to let you know the substance you are searching for has changed.
When complete you will get an analysis of the sample; click on the analysis to continue and get the CHEMICAL X.
Click on the door upstairs and click on the left display case to access a Hidden Object Scene.

Click on the glass display case (in red) and take the SEDATIVE DARTS.
Find the items listed.

Use the SEDATIVE DARTS on the barking dog (P).
Click on the top of the stairs (Q).
Look close at the emblem on the door.
Complete each section by clicking on the center of each segment till the correct image appears to complete each scene. See screenshot for solution (R).

Use the BOLT CUTTER on the chains (S).
Try and take the sword (T).
Speak to Madame Oracleaux.
Take the GOLDEN SWORD (U) from the ground.
Head forward two times into the cemetery.
Click on the lower left gravestone to access a Hidden Object Scene.

Find the items listed.
Get a MUSIC CYLINDER added to your inventory.
Head straight past the crypts.

Take the BUG REPELLENT (V).
You should now have all the ingredients (BLUE EGGPLANT, BUG REPELLENT, BLUE BEETLE and CHEMICAL X) needed for the moss solvent and you will automatically combine them to get the MIX SUBSTANCE: MOSS SOLVENT.
Use the SEDATIVE DARTS on the meat (W).
Use the sedative laced meat on the hook (X) and the alligator will go to sleep.
Place the MIX SUBSTANCE: MOSS SOLVENT on the PCI Field Kit.

The goal is to clear the board by matching all of one color together to eliminate them in the number of moves listed in the upper left.
You can move the samples by clicking on any two touching substances to switch them or by clicking on the left or right arrow to rotate the screen 90 degrees.
Any three of a kind touching each other will automatically clear off the board, so be sure they do not touch until all of one color can be combined.
See screenshot for solution.
Get a MOSS SOLVENT when complete.
Head forward three times to the lake house.

Use the MOSS SOLVENT on the body (Y).
Take the third IRON STAR (Z).
Back out five times to the memorial and left one time.
Click on the barrier to trigger a puzzle.

The goal is to line up the rings to complete the symbol.
Turning some of the rings will turn other rings; the rings affected will turn purple.
The symbol will turn yellow if correct.
Turn the inner ring 1 to line up with ring 2.
Turn ring 2 (automatically turn 1 with it) until they turn yellow (A).
Turn ring 3 until it turns yellow.
Turn ring 4 until it lines up with the outer ring 5 (B).
Turn outer ring 5 (automatically turn 4 with it) to complete the symbol (C).
Head to the left and click to the left of the stage stairs to access a Hidden Object Scene.

Find the items listed.
Get a MUSIC SHEET added to your inventory.
Look close at the pipe organ.

Take the ORGAN BONES (D) and the SKULL (E) and automatically combine them to get a DATABASE ID SCAN: BONES.
Place the DATABASE ID SCAN: BONES in the PCI Field Kit.
Place the MUSIC SHEET on the music stand (F).
Place the 2 PIPES to the right of the music stand (D) where the bones were.
Place the MUSIC CYLINDER in the compartment (G) on the right.

The goal is press the matching keys on the keyboard to duplicate the music highlighted in green on the sheet music.
The black notes are the black keys and the white notes are the white keys on the keyboard.
The left half of the keyboard is for the black and white notes that have a single dot under them and the right half is for the double dots.
There is no timer and the notes that have been completed will be highlighted in green on the sheet music (I).
Take the 4th IRON STAR (H) when complete.
Back out of the area two times to the memorial and speak to Madame Oracleaux.
Automatically get CALVIN'S POTION #42 after speaking to Madame Oracleaux.
Back out two more times and head left to the cathedral gates.

Chapter 3 - The Crescent Snake

Look close at the lock (J) on the gate.
Place the 4 IRON STARs on the lock (K) and the gate will open automatically.
Click on the area to the left of the gate to access a Hidden Object Scene.

Click on the leaf covered rocks (in red) on the lower left to get the HELM.
Find the items listed.
Enter through the opened gate.
Click on the pedestal on the right to access a Hidden Object Scene.

Click on the egg (in red) to break it and take the cracked egg.
Find the items listed and get a GILDED STAFF.
Use the winch on the well on the left to pull up a bucket and note we need to place something underneath the lid.
Click on the sundial on the right and note the missing part of the arrow.
Click on the doorway to the cathedral and click again to enter.
Click on the green symbol on the floor of the cathedral.

Click and drag the slabs scattered throughout the cathedral to their matching spots over the lava by matching the shapes. See screenshot for solution.
Look close at the altar and note the coins.
Head into the chamber on the left.

Take the BURNT-OUT TORCH (L).
Use the BURNT-OUT TORCH on the candles (M) to get a LIT TORCH.
Click on the sword (N) and note you need a ladder.
Click on the trap door and note it is locked from the other side.
Note the missing mirror (O).
Click on the closest door on the right and note the missing coins.
Look close at the 2nd door (P) to the right to access a puzzle.

The goal is to slide the pieces to complete the symbol (Q).
Solution; click on the squares in the order numbered on the screenshot.
Head into the newly-opened door.

Place the LIT TORCH on the wall (R) to the left.
Click on the green symbol on the left wall and the snakes on the floor.
Head forward down the hall and take the TORCH (S).
Back out one time and use the TORCH on the LIT TORCH (R) on the wall to get a LIT TORCH.

Head forward down the hall and place the LIT TORCH on the wall in the upper left (T).
Place the GILDED STAFF on the bucket (U).
Look close at the green glowing barrier (V) on the right.

The goal is to align all the rings to complete the symbol.
When the ring is in the correct position it will turn yellow.
Turning some rings will cause other rings to turn. Rings that are affected will be highlighted in purple.
Turn ring 1 until it turns yellow.
Turn ring 2 until it turns yellow.
Turn ring 5 until it turns yellow; ignore the 3rd ring that turns with it.
Turn ring 3 until it turns yellow.
Turn ring 6 to line up with ring 7.
Turn ring 7 (automatically turn ring 6 with it) until it turns yellow.
Turn ring 4 until it turns yellow and the puzzle is complete.
Click on the pulsing yellow stone slab on the right to open the passage.
Click on the pile of items in the right corner of the room to access a Hidden Object Scene.

Find the items listed.
Get an ARROW added to your inventory.
Head through the opening on the right.

Pick up the TRIANGULAR MIRROR (W).
Click on the end of the tunnel (X) two times.
Back out four times and head down the left road two times to the well.
Click on the pedestal on the right to access a Hidden Object Scene.

Find the items listed.
Get a SQUARE MIRROR added to your inventory.

Place the ARROW on the sundial (Y).
Crank the handle on the well (Z) to lift off the lid.
Place the SQUARE MIRROR on the top of the well (A).
Get the recipe for the swan's tears from Madame Oracleaux added to your PCI Field Kit.
Enter into the cathedral and head to the left.

Place the TRIANGULAR MIRROR on the triangular slot on the left (B).
Click on the mirror (C) in between the doors on the right so that there are two beams going through the doorway.
Head into the right doorway where the beams are and straight down the hall.
Click on the items piled in the right corner to access a Hidden Object Scene.

Open the book in the center (in red) and get the feather.
Find the items listed and get a MUSHROOM.
Head to the right, click on the end of the tunnel two times to exit.
Back out of the crypt and head forward five times and up the fire escape.
Click on the glass display case on the left to access a Hidden Object Scene.

Find the items listed and get BERRIES.
Back out nine times and head right to the Café du' Globe and head right twice to the pier.

Move the newspapers and take the REEL (D).
Place the REEL on the pole (E).
Click on the reel until the fish is landed.
Take the MISSISSIPPI BASS (F).
Back out two times and head left once, forward twice via the street on the right and left one time and enter Madame Oracleaux's shop.
Take the CRANE CONTROL BUTTON (G).
Back out two times and head forward six times.

Look close at the crane cabin (H).
Place the CRANE CONTROL BUTTON on the right panel (I).
Turn on the crane by turning the key (J).
Click the up button on the CRANE CONTROL BUTTON.
Head straight one time under the raised beams to the Cul-de-sac.

Reassemble the statue by clicking and dropping the pieces in place on the pedestal.
You can click the pieces anywhere on the statue and if done in the correct order they will place themselves when you release them. See screenshot for solution.
Place the HELM on the assembled statue.
Look close at the blue gem (K) to trigger a puzzle.

The goal is to burn off all the moss with the beam of light.
Use the arrows to move the light.
One Solution; L, L, L, U, R, R, R, U, L, L, L, U, R, R, R.
Take the clean GUARDIANS' SHIELD.
Place the GUARDIANS' SHIELD and the GOLDEN SWORD on the statue.
Take the GOLD COIN (M) from the flowers.
You should have all the ingredients for the Swan's Tears and automatically combine the BERRIES, MISSISSIPPI BASS, MUSHROOM and GOLD COIN to get MIX SUBSTANCE: SWAN'S TEARS.
Place the MIX SUBSTANCE: SWAN'S TEARS on the PCI Field Kit.

The object is to catch the substances floating around that match the highlighted substances on the left.
When the next substance is to be found they will enlarge and flash briefly on the screen to let you know the substance you are searching for has changed.
When complete you will get an analysis of the sample; click on the analysis to continue.
Get SWAN'S TEARS added to your inventory when complete.

Use the SWAN'S TEARS on the flames (A) around the statue.
Take the CLEAR BLUE CRYSTAL (B) from the ground to the left of the statue.
Back out nine times and head right to the Café du Globe.
Officer Zach gives you a SNAKE GRABBER.
Head left one time.

Look close at the box of snakes (N) and remove the lid if you did not do it earlier.
Use the SNAKE GRABBER on the box of snakes to trigger a puzzle.
The goal is to remove the snakes from the box removing only the top snake each time. See screenshot for the order to remove the snakes.
Take the ROPE LADDER after the snakes have been removed.
Head down the street on the left two times to the cathedral grounds.

Place the ROPE LADDER on the well (O) and climb down.
Back out one time.
Look close at the projector (P) on the right.

Take the BLACK CRYSTAL at the top of the inside of the box (Q).
Place the CLEAR BLUE CRYSTAL where the BLACK CRYSTAL was located.
Rotate the mirrors so that a beam lights up each of the three blue crystals on the bottom. See screenshot for solution.
Take the MEDALLION (R) from the left.
Click on the insignia and keyhole on the left.
Head straight down the hall and go right, click on the end of the hall two times to enter the crypt.
Back out of the area four times and head left and forward into the cathedral.
Look close at the altar.

Use the SWAN'S TEARS on the coins (S).
Take the 6 coins to get CALVIN'S COIN, ASTRONOMER'S COIN, MEMORIAL SHRINE COIN, PETER'S COIN, GEORGE'S COIN and the GUARDIAN'S COIN.
Speak to Madame Oracleaux and get a Guardian's Miracle Ingredients list added to your log.
Back out two times, head down the right path two times, head left two times to the jazz club.
Click on the area to the left of the stairs to access a Hidden Object Scene.

Find the items listed and get a RECORDING DEVICE.
Use the RECORDING DEVICE on the top of the organ pipes to get a FILLED RECORDER.
Back out of the area two times and go forward into the cemetery.

Take the WHITE PIGMENT (T) on the glowing symbol on the right.
Head straight three times to the bayou and take a PURPLE LOTUS (U).
Head straight three times to the cul-de-sac and take the GUARDIAN'S BLOSSOMS (V).
You should have all the ingredients needed for the Guardian's Miracle (WHITE PIGMENT, PURPLE LOTUS, GUARDIAN'S BLOSSOMS, BLACK DIAMOND and FILLED RECORDER) to automatically combine them into MIX SUBSTANCE: GUARDIAN'S MIRACLE.
Place the MIX SUBSTANCE: GUARDIAN'S MIRACLE on the PCI Field Kit.

The goal is to clear the board by matching all of one color together to eliminate them in the number of moves listed in the upper left.
You can move the samples by clicking on any two touching substances to switch them or by clicking on the left or right arrow to rotate the screen 90 degrees.
Any three of a kind touching each other will automatically clear off the board, so be sure they do not touch until all of one color can be combined.
See screenshot for solution.
Get the GUARDIANS' MIRACLE when complete.
Back out if the area nine times and head down the left path to the cathedral courtyard.
Speak to Madame Oracleaux and get a SWAN KEY.
Head down the well and back out one time.

Use the SWAN KEY on the lock (W) on the left passage.
Enter into the passage on the left.
Look close at the first door on the right (X).

Place CALVIN'S COIN, ASTRONOMER'S COIN, MEMORIAL SHRINE COIN, PETER'S COIN, GEORGE'S COIN and the GUARDIAN'S COIN on the symbol on the door (Y).
Place the MEDALLION in the center (Y).
Enter into the newly-opened door.

Take the LADDER (Z).
Back out of the area one time.
Place the LADDER on the far end of the room (A).
Take the SWORD (B).
Take the LADDER (A).
Head back into the first door on the right.
Use the SWORD on the three ropes holding the bell (C).
Place the LADDER by the bell and look close at the bell (D).
Use the GUARDIANS' MIRACLE on the each of the blue writings (E) until they are gone.
Use the CALVIN'S POTION #42 on the purple symbol.

The goal is to use the CALVIN'S POTION #42 to trace the symbol.
If you get off track you will need to dip the applicator into the bottle again, but you will not lose your progress.
You can apply the potion by click-holding the mouse and dragging it along or by clicking sections at a time.
See screenshot for solution (F).
Congratulations! You have successfully completed Paranormal Crime Investigations: Brotherhood of the Crescent Snake Standard Edition.