Hell is Us Investigation Items Guide

This Hell is Us Investigation Items Guide will tell you what Investigation Items are, how they work, and where you can find them in Hadea.

How Investigation Items Work

Hell is Us Investigation Items are very important items that are typically used to advance the story. They're essentially the same as Exploration Items, but they're much more important overall. These items can include keys, maps, notes, and other items that are used to solve puzzles, provide clues, or otherwise advance your progress.

In some cases, Investigation Items will disappear once they are used for a particular task. Other Investigation Items will stick around for the rest of the game as long as you have them. (Man, you must have some pretty deep pockets!)

Below, you'll find a list of every Investigation Item we've come across, its Location, specific directions to that item, and what it's used for.

Hell is Us Investigation Items List

Investigation Item	Location	Specific Directions	Used For
Advanced Lymbic Forging	Auriga Museum	Complete all protocols in the B4 Timeloop Weaponization room. Then head to the Stock Room on the other side of the room.	Increases Victor Gaz's Blacksmithing capabilities.
Ancient Lymbic Forging	Plains of Mist	After Gorge of Our Sacrement test room and down hall with minor enemies; yellow indicator on right side, opposite Lymbic Chest	Increases Victor Gaz's Blacksmithing capabilities.
Ancient Lymbic Forging	Senedra Forest	Found at the top of the stairs after the Arcas Spire door puzzle	Increases Victor Gaz's Blacksmithing capabilities.
Ancient Mechanism	Senedra Forest	Given to you by the soldier OMSIF-0451 after you give him the OMSIF Medkit	Used to open up the stone door near the APC
Blue Flower Scroll	Vyssa Hills	Received from Tania Alver after solving the puzzle of Pentos Algea in The Watcher's Nest, showing the scroll to Gildas Brom, and returning to the APC and having Tania investigate it.	Hints at how to drain the Lake Cynon reservoir.
Ceramic Flower	Vyssa Hills	4 found on the stone coffin underneath the Watcher's Nest	Used to solve the Puzzle of Pentos Algea in the Watcher's Nest.
Compass	Senedra Forest	Owned by default	Shows your direction when used
Drone Processor	Auriga Museum	B3 Drone Lab through the Drone Workshop, accessed with the keycode 230317 as told to you by Dr. Marga Hamil.	Given to Dr. Marga Hamil on level B3 so she can repair her drone.
Emblem - Book	Vyssa Hills	Found on Agatha Maren's dead body near Tania Alver; head northwest away from her initial spawn point, then turn left and head south down the road. You'll find it on a corpse just past the broken wooden scaffolding.	One of two keys to the Watcher's Nest
Emblem - Candle	Vyssa Hills	Given to you by Tania Alver after you meet her for the first time and talk with her.	One of two keys to the Watcher's Nest
Ethnic ID Card - Agatha Maren	Vyssa Hills	Found on Agatha Maren's dead body near Tania Alver; head northwest away from her initial spawn point, then turn left and head south down the road. You'll find it on a corpse just past the broken wooden scaffolding.
Family Picture	Acasa Marshes	Found in a back room in Vitalis' House in the Village of Jova	Used to open up the basement in Vitalis' house.
Family Picture	Acasa Marshes	Found in a back room in Vitalis' House in the Village of Jova	Used to open up the basement in Vitalis' house.
Family Picture	Acasa Marshes	Found in a chest in the basement of Vitalis' House in the Village of Jova	Used to open up the basement in Vitalis' house.
Fundamentals of Lymbic Forging	Lake Cynon	Found in the coffin of Kalvin Modus, at the bottom of the elevator deep in the Lymbic Forge.	Increases Victor Gaz's Blacksmithing capabilities.
Gear - Large	Lake Cynon	Found in a chest in the room behind the Lymbic Forge's chapel pulpit, in the area below the Lymbic Forge's hammer door after you've pumped out additional water	Fits on the right side of the device opposite the hammer door in the Lymbic Forge. Completely drains the water in the area.
Gear - Spindle	Lake Cynon	Retrieved by completing the Lake Cynon reservoir puzzle	Allows you to pump out the water in the Lake Cynon reservoir.
Gear - Spire	Senedra Forest	Found in the large underground cave on the far eastern side of Arcas Spire.	Needed to repair the elevator in Arcas Spire.
Gear - Spoked	Lake Cynon	Found in a chest north of The First Library in the Lymbic Forge (the temple underneath Lake Cynon's reservoir)	Fits on the left side of the device opposite the hammer door in the Lymbic Forge. Lowers the water further in the immediate area.
Gospel of Teaar	Lethe - National Library	Found on a desk in the locked Book Restoration Office in the basement, accessed with the passcode 537734 as detailed in the Note - Keycard Reminder.	Hints at where to find the Keystone of Ecstasy.
Guardian Detector	Vyssa Hills	Received from Gildas Brom after solving the puzzle of Pentos Algea in The Watcher's Nest	Points toward the nearest Timeloop Guardian when active.
Hammer of Modus	Lake Cynon	Found in the coffin of Kalvin Modus, at the bottom of the elevator deep in the Lymbic Forge.	Allows you to open the door to the actual Lymbic Forge.
Heirloom Necklace	Senedra Forest	Owned by default	Used to open the chest in the basement of Vitalis' House in the Village of Jova
Historical Lethe - City of Wonder	Lethe - National Library	Found in the Classics section in Embry Hall	One of the books used to decode the password to the Book Restoration room in the basement of the library.,
Iron Seal - Fading	Jeljin	Found in the tomb under the church courtyard, which you access by solving the church courtyard combination lock.	Placed in the left slot of the door under Auriga Museum.
Iron Seal - Rising	Lethe - Ministry of Cultural Primacy	In Marton Ralst's Safe on the fourth floor of the Ministry of Cultural Primacy; the safe is opened with code 203279.	Placed in the right slot of the door under Auriga Museum.
Journal - Auriga Entrance	Lethe - Ministry of Cultural Primacy	In Marton Ralst's Safe on the fourth floor of the Ministry of Cultural Primacy; the safe is opened with code 203279.
KATOCHE Datapad	Senedra Forest	Owned by default	Manage your inventory
Key - Caddell Farm	Senedra Forest	Acquired by talking to Ernest Caddell in the basement of the yellow house on his farm in Senedra Forest	Opens the fence to Senedra Forest
Key - Crying Eye	Lake Cynon	Found on a stool in the kitchen of the Lymbic Forge (the temple underneath Lake Cynon's reservoir). Head north through the mess and turn west at the first intersection tunnel to reach the kitchen.	Opens the door near the second floor of the Lymbic Forge's Chapel. Go up to the second floor's eastern side, head east down the hallway, turn south after a few meters, and then turn east to find the door.
Key - Mine	Vyssa Hills	Near the ruins with the moon symbol after you go through the door with the Token of the Serpent.	Opens up locked doors in the mines marked with the pickaxe symbol.
Key - Owl	Lake Cynon	Found on a skeleton in the Lymbic Forge (the temple underneath Lake Cynon's reservoir), southwest of the hammer door to the actual Lymbic Forge	Opens the door east of the fireplace in the quarters of the Scholars of the Order of the Eye in the Lymbic Forge, the wing south of the entrance hall.
Key - Parking Lot	Talju	Given to you by Caspian Fran in the Town Hall after you rescue his son	Opens up the door to the security office in the parking lot behind the Town Hall, which gives you access to a computer that opens the gate
Key - Pharmacy	Talju	On a corpse leaning over the railing of a pedestrian bridge east of the Playground	Opens up the back door to the Pharmacy, which you can only access once the ON truck moves. The truck will move after you rescue Caspian Fran's son and kill the enemies in the parking lot per his request.
Key - Rusted (Arcas Spire, Balcony)	Senedra Forest	Received after defeating the boss at the end of Arcas Spire.
Key - Rusted (Temple of the Fallen)	Plains of Mist	Across the wooden bridge after the first two Sacraments in the Gorge of Our True Sacraement.	Used to open a nearby door.
Key - Statue	Marastan	Given to you by Talis on the balcony of a building in the highest part of town.	Opens up the gate to the Blood Queen Statue.
Key - Vitalis' Home	Acasa Marshes	Found in the tunnel on the way to the ON Convoy, in the northeast of the Acasa Marshes; speak to Victor Gaz to get it	Opens the door to Vitalis' Home opposite the blacksmith shop in the Village of Jova
Keycard - Clearance Alpha	Auriga Museum	Rescue Seo Kagin from the B1 Training Room	Opens up doors in the facility under Auriga Museum.
Keycard - Clearance Beta	Auriga Museum	Obtained from Distressed Scientist on B3 in exchange for Drone Processor	Opens up doors in the facility under Auriga Museum.
Keycard - Clearance Delta	Auriga Museum	B4 Supply room	Opens up doors in the facility under Auriga Museum.
Keys - Crane	Jeljin	Found on the far side of the church; reach them by climbing the scaffolding attached to the church and going over its roof	Used to unlock the controls of the crane north of the church, opening up access to the Dagger Masuoleum.
Keys - Lethe National Library	Lethe - National Library	Given to you by Iblis on the second floor after talking to him.	Opens up the hallway next to Embry Hall on the first floor
Keys - Maintenance	Auriga Museum	Floor B2 on the desk	Opens up doors in the facility under Auriga Museum.
Keystone of Ecstasy	Plains of Mist	Rapturous Dance alter by defeating the boss; kill small entities to fill the yellow gauge and deplete the red one, then a large one.	One of the Keystones needed to open the door in the Lymbic Forge.
Keystone of Grief	Vyssa Hills	Given to you by Vitalis when you meet him near the Weeping Knight statue	One of the Keystones needed to open the door in the Lymbic Forge.
Keystone of Rage	Auriga Museum	Complete all protocols in the B4 Timeloop Weaponization room. Then interact with the contamination pod on the opposite side of the room as the timeloop	One of the Keystones needed to open the door in the Lymbic Forge.
Keystone of Terror	Senedra Forest	Top of the Arcas Spire after clearing the timeloop; defeat the boss of Terror to acquire it.	One of the Keystones needed to open the door in the Lymbic Forge.
Lady Merguerith: Scandal and Steel	Lethe - National Library	Found in the Languages section in Embry Hall	One of the books used to decode the password to the Book Restoration room in the basement of the library.,
Letter - Land Grant	Vyssa Hills	In the temple past the door with the palm symbol, which is opened after you've opened the doors with the serpent symbol and moon symbol.	Reveals the Plains of Mist on the map.
Lymbic Imbuing	Acasa Marshes	In the trunk of the car directly north of the hanging tree in the marshes, which is opened with the key on the porch of Vitalis' house opposite the blacksmith shop	Increases Victor Gaz's Blacksmithing capabilities.
Map of Acasa Marshes	Acasa Marshes	Found next to the ON Outpost in the Village of Jova	Can be used to show you the route for the ON convoy in the Acasa Marshes
Map of Hadea - Ancient	Jeljin	Found in the tomb under the church courtyard, which you access by solving the church courtyard combination lock.	Hints at something being under the Auriga Museum.
Map of Talju	Talju	Received by speaking to Boro Juven in the garage of his mechanic's shop The Toolshed, north of where your APC first enters Talju.	Shows you critical locations in Talju.
Note - Keycode Reminder	Lethe - National Library	Found on Locke's body in the locked hallway next to Embry Hall on the first floor
Note - Lymbic Locks	Acasa Marshes	Located in the keypad-locked room within Vitalis' basement in the Village of Jova	Explains how Lymbic Locks work.
Note - Wall Grooves	Vyssa Hills	Found at the start of the Watcher's Nest	Hints how to solve the Puzzle of Pentos Algea in the Watcher's Nest.
OMSIF Medkit	Senedra Forest	At the OMSIF camp up the road past the APC	Used to help the OMSIF soldier found near the APC.
Orb - Cobalt	Lake Cynon	Through the keystone door towards Mount Obek. Found in the Eye of God room.	Used to solve the final puzzle of the game in the Failsafe Room.
Orb - Crimson	Lake Cynon	Through the keystone door towards Mount Obek. Found in the Eye of God room.	Used to solve the final puzzle of the game in the Failsafe Room.
Orb - Emerald	Lake Cynon	Through the keystone door towards Mount Obek. Found in the Eye of God room.	Used to solve the final puzzle of the game in the Failsafe Room.
Orb - Gold	Lake Cynon	Through the keystone door towards Mount Obek. Found in the Eye of God room.	Used to solve the final puzzle of the game in the Failsafe Room.
Scroll - Failsafe	Lake Cynon	Found in the room after opening the door with the four Keystones.	Defines the symbols on the eight statues in the Failsafe Room for the final puzzle in the game.
Scroll - General Aarlon's Note	Senedra Forest	Found at the top of the stairs after the Arcas Spire door puzzle	Explains where you'll find the Keystone of Terror.
Scroll - Queen's Eulogy	Marastan	In the Blood Queen's Tomb. Retrieved by entering the correct combination in the lock: crossed swords, crown, eye, tower.	Hints that you should visit the Arcas Spire in Senedra Forest.
Sigil - Order of the Eye	Lake Cynon	In the Lymbic Forge (the temple under the Lake Cynon reservoir), found behind a hidden door in a fireplace. You need to activate the two levers to the north and the two levers to the south to open the secret door.	Slots into the right side of The Great Atrium door in the Lymbic Force, the temple underneath the Lake Cynon reservoir.
Sigil - Phol Guard	Lake Cynon	In the Lymbic Forge (the temple under the Lake Cynon reservoir), found in the pit with the vertical shaft and gears in the room north of the mess hall right at the start of the area.	Slots into the left side of The Great Atrium door in the Lymbic Force, the temple underneath the Lake Cynon reservoir.
Sword of the Blood Queen	Marastan	In the Blood Queen's Tomb. Retrieved by entering the correct combination in the lock: crossed swords, crown, eye, tower.	Used to open Arcas Spire (the massive tower) in Senedra Forest.
Tablet Fragment - Angled	Marastan	Down the southern path of the tombs under the Marastan graveyard. Go down the southern tunnel, then turn left, right, left, and right.	One of three tablet fragments used to open up the tomb of the queen in Marastan.
Tablet Fragment - Oblique	Marastan	Down the northern path of the tombs under the Marastan graveyard. Go down the northern tunnel, then go left, left again, and right.	One of three tablet fragments used to open up the tomb of the queen in Marastan.
Tablet Fragment - Square	Marastan	Down the northern path of the tombs under the Marastan graveyard. Go down the northern tunnel, then go left, right, and right again.	One of three tablet fragments used to open up the tomb of the queen in Marastan.
The Loblina Alliance	Lethe - National Library	Found on a western bookcase in Embry Hall	One of the books used to decode the password to the Book Restoration room in the basement of the library.,
The Quill and the Pyre: The Legacy of Sabin Gau	Lethe - National Library	Found on a bookshelf toward the rear of Computer Room D on the second floor	One of the books used to decode the password to the Book Restoration room in the basement of the library.,
Token of the Moon	Vyssa Hills	Once you have the Key - Mine, head northwest from yourt APC and climb the ladder onto the wooden scaffolding. Take a right and climb down the mineshaft a short distance away. Then, follow the white mouse symbols until you see a ladder going up on the right wall; this will take you into a closed-off area with the Token of the Moon	Used to open the door with the moon symbol after you've unlocked the door with the serpent symbol.
Token of the Palm	Vyssa Hills	In the large courtyard area past the door opened with the Token of the Moon.	Used to open the door with the palm symbol after you opened the door with the serpent symbol and the door with teh moon symbol.
Token of the Serpent	Vyssa Hills	Enter the Bishur Mines near the Weeping Knight statue. Take the first left, follow the minecart tracks until you reach a ladder and climb up. You'll find a chest that you can open with the Twin-Headed Serpent emblem you acquired in Lethe - National Library.	Used to open up the door with the serpent emblem in the Vyssa Hills.
Twin-headed Serpent	Lethe - National Library	Found on a desk in the locked Book Restoration Office in the basement, accessed with the passcode 537734 as detailed in the Note - Keycard Reminder.	Used to open the chest in the ruins at the top of the mineshaft in Vyssa Hills, giving you access to the Token of the Serpent.
Vigil Note	Acasa Marshes	Located in the keypad-locked room within Vitalis' basement in the Village of Jova	Tells you where to go in Vyssa Hills.
Walkie-Talkie	Talju	Given to you by Caspian Fran in the Town Hall	Used to help rescue Caspian Fran's son.

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Robert N Adams | Senior Writer

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