AI: The Somnium Files Wiki
AI: The Somnium Files Wiki

SINKIN' IN THE BRaiN is a dreamworld featured in AI: THE SOMNIUM FILES based on the Sagan Residence.

It is a Somnium world created from Kaname Date's dream while napping at the Central Hospital. It acts as a tutorial for Somnium puzzles.


Summary image 004.png

Date began his dream in an unfamiliar room, his memories clouded, and is greeted by an unfamiliar transparent woman dancing behind a skeleton sitting on the couch. The woman was Aiba, appearing in her brand new human form, which Date hasn't seen before. She told Date who she was, and explained Somnia and Mental Locks to him, after which Date began directing her through his dream. During her explanation, the figure of a man appeared briefly. Date told Aiba he did not recognize him, but she said he must know, since dreams are created from memories.

Aiba determined that she was only able to interact with the Somnium is through the colored objects in the room, shining on various light sources, so they needed to light up more of the room to progress. After she turned on the lights in the room to break the first Mental Lock, a woman briefly appeared on the couch.

Punching the head off the skeleton on the couch caused the room to crumble. Aiba fell through the floor and landed once more in the same room. There, she watched the figure of the same man from before walk through the front door. Once more, Date insisted he did not know who he was.

Aiba used the gun-shaped key to unlock the door. She opened it to reveal the woman from before, motionless and bleeding on the floor, and the same man, a gun in his hand. As he began to turn around, Date woke up.

Mental Locks

Mental Lock #1 - Turn on the light.

Mental Lock 1 BRaiN.jpg

The Somnium begins with a guided tutorial within the room. With the lack of any timer found within the Somnium, there is no penalty to interacting with all optional choices within the Somnium, giving anyone free roaming across the room as long as they don't progress too far.

The only object that can be interacted with at the beginning is the Door, and the only option available is Investigate. In doing so, the tutorial progresses, as the Door becomes inaccessible and the Light Switch and the Winter Iris become available with the small sliver of light.

Both the Light Switch and Winter Iris have two possible interactions, but Aiba must interact with the Winter Iris first before the Light Switch is capable of doing any action. By selecting Smell, the Winter Iris is removed in favor of allowing access to the Light Switch. Select Turn On Switch and light flows into the room, removing Mental Lock #1.

In summary, to unlock Mental Lock #1: Investigate on Door -> Smell on Winter Iris -> Turn On Switch on Light Switch

Mental Lock #2 - Open the door.

Mental Lock 2 BRaiN.jpg

In the second Mental Lock, three objects are available to interact with: Standing Lamp, Basket, and Wine. Each object has 3 actions featuring optional dialogue, but 1 in each blocks access to that object for the rest of the Somnium. With the Standing Lamp, the choices Lift Up and Turn Off Light are optional, while the choice Kick prevents further interaction. With the Basket, Wear Basket and Tackle are optional, but Search progresses. And with the Wine, Investigate and Smell are optional while Take a Sip progresses.

Progressing with all the objects listed above opens up interactions with the Skeleton. Selecting Kick on the Standing Lamp unlocks the choice Hit on the Skeleton. Selecting Search on the Basket unlocks the choice Investigate on the Skeleton. And selecting Take a Sip on the Wine unlocks the choice Talk on the Skeleton. Within this choice chart, most of the actions are optional, but selecting the action Hit on the Skeleton progresses the Somnium itself and changes the layout, removing access to the other objects and choices around.

At this point in the stage, the Hidden Item is available to be located. The game gives a hint of its newfound presence during its tutorial, and the object can be found on the kitchen sink nearby.

After hitting the Skeleton, only two objects become available: the Door once again and the Gun. The Door holds new interactions, but none of them progress further. The Gun, on the other hand, has the option to Pick Up or Investigate. By picking it up, the Door can be unlocked. The choice Put Gun in Keyhole on the Door is the final choice in the Somnium, and selecting it will end the level.

In summary, to unlock Mental Lock #2: Kick on Standing Lamp -> Hit on Skeleton -> Pick Up on Gun -> Put Gun in Keyhole on Door.

Objects of Interest

Object Description
Availability Action Coss TIMIE Effect
Door A door that leads outside the apartment. It has a series of chains and a padlock blocking access outside.
Lock #1 Only Investigate N/A N/A
Investigating the door will lead to the conclusion that Aiba must open the door. When she reaches for the doorknob, however, she realizes that she cannot physically touch the door itself, which she notes is to be expected within Date's Somnium. When Date asks, confused, Aiba prepares to explain, which he then shoots down in favor of falling asleep again. Noting how light has poured into the room, Aiba points out that wherever the light touches, its surface regains color, and therefore tangibility. While explaining, the figure of an unknown man appears for a brief instance, which neither Aiba nor Date himself recognize. She encourages Date to keep exploring his own Somnium to clear the Mental Locks, but reminds him that she has a veto against his choices.

This action leads further into unlocking Mental Lock #1.

Lock #2

(Select Hit on Skeleton)

Attempting to open the door will yield no results, as the door is sealed shut by the padlock. Date comments on how his dreamscape is all about staying smart and level-headed, which Aiba remarks as a lie. She doesn't believe him when he claims that's just who he is.
Attempting to knock on the door will have Aiba give the call "Knock knock and hello!" to the recipient on the other side. Date notes the reference she made, and she reponds by saying she just wants to be an A.I. beloved by all. The door remains unaffected by the knocking, however, which Date suggests may be because he doesn't really get the joke.
Attempting to tackle the door down will yield no results. Aiba admits she thought it would work, since she states Date has a musclebrain. Date plays along with her comment, acting like someone with low vocabulary, much to Aiba's dismay.
Lock #2

(With Gun)

Put Gun in Keyhole
Aiba questions that the gun could even fit inside the lock of the door, while Date suggests she puts in "just the tip." Doing so will have the padlocks and chains break off, where Aiba realizes that the gun was actually the key all along, and Date makes a joke about him being the "key" to solving the Somnium. They both declare the dream over and open the door, where they both discover the mysterious man standing in the room, facing away from them, and the body of the mysterious woman bleeding on the ground.

This action unlocks Mental Lock #2, awakening Date from his dream!

Suggesting to shoot the door open will have Aiba enthusiastically have her aim at it. She begins with the saying "There are two kinds of people in the world. Those who open doors..." before Date interrupts her to just shoot. At the press of the trigger, a flower appears at the end of the gun, instead of a bullet. Aiba tells the door that it got lucky.
Winter Iris An iris flower on a pot, specifically named a winter iris for blooming in winter. Date seems rather curious at seeing a flower named after a woman's name.
Lock #1

(Select Investigate on Door)

Grab N/A N/A
Attempting to grab it off the stool yields no result, as Aiba notes it is stuck remarkably down on the surface. Date reflects on how it's symbolic of his lifestyle of setting down his roots and standing his ground, while Aiba pitches in about how it could reflect his "inconvenient annoyance."
Attempting to smell the plant will have Aiba pantomime the action of "smelling" to help visualize the action, which Date points out. When the action yields no results, Date insists that she must smell the flowers harder. Confused by his words, Aiba attempts to smell it again, but now at full force, which pulls the plant and the nearby thorns with incredible strength up to her nostrils, clogging her nose as she falls backwards. Date cheers for her amazing suction, and then Aiba questions why this kind of action would occur within his dreams in the first place.

This action removes the Thorns on the Switch.

Switch A switch on the wall by the photograph. When first investigated, it is covered in thorns. After the Winter Iris has been removed from its stool, the thorns vanish as well.
Lock #1

(Select Investigate on Door)

Pull Thorns N/A N/A
Realizing that things must be completed in order, Aiba attempts to pull off the thorns from the switch. However, the thorns were unable to be removed, instead receiving pain from the contact. Date notes, however, that it has indeed gained tangibility as stated before.
Turn On Switch With Thorns:
Aiba tries to dissuade Date from making her turn on the switch, explaining how their consciousnesses are linked, but he insists she turn on the switch anyways. Aiba attempts to do so, which results in her finger being pricked. Date apologizes, saying he doesn't feel the same pain she does, much to Aiba's anger.
Without Thorns:
Aiba manages to flip the switch without problems, giving light and color into the room. In doing so, the figure of a mysterious woman briefly appears sitting on the sofa, before disappearing just as fast. Aiba tries to encourage him to feel rewarded for his actions, but Date simply grumpily comments he would rather be sleeping.

This action unlocks Mental Lock #1!

Standing Lamp A pink floral lamp shaped like a rose, about the size of Aiba herself.
Lock #2 Only Kick N/A N/A
Kicking the lamp doesn't make the lamp budge from its spot. Date reprimands her for kicking it too hard, but Aiba insists that she always gives it everything she's got. While Date notes the lamp did not move, Aiba points out how the skeleton's head shook when she kicked it. She asks if they're gonna "get him too", which Date thinks makes her sound like a thug.

This action leads further into unlocking Mental Lock #2.

Lift Up
Attempting to lift off the lamp will keep it in place, as it appears stuck to the ground. Date reflects on how this is symbolic on his unflinching will, holding his ground like a mountain, while Aiba pitches in about how it could reflect his "irritating personality spreading like pollen in the wind." Date's eyes begin watering, claiming its from allergies, while Aiba suggests he's just sleepy.
Turn Off Light
Attempting to turn off the lamp ends up being fruitless, as there is no switch or plug on the lamp. Date continues complaining about how he simply just wants to go to sleep. Aiba and Date note that this house is not Date's house, but someone else's, perhaps from his memories. He does not seem to remember whose, however. Aiba elaborates on how this house could be pieced together from individuals Date has a strong personal connection, and insists that the light remains on so she could see more (which Date points out sounded dirty).
Basket A basket within the bookcase. Aiba can't see inside the basket while it remains inside.
Lock #2 Only Wear Basket N/A N/A
Wearing the basket will have Aiba note that it is dark inside and she cannot see anything. Date notes what he can see, which is "a dumb A.I. and a skeleton." When Aiba put on the basket, a similar basket appeared on the skeleton's head.
Attempting to tackle the basket will cause Aiba to tackle the basket... and the entire bookcase as well. As she complains from the pain, Date apologizes for making her do so, telling her that she now must "shoulder that burden". Aiba doesn't take the pun humorously.
Searching the basket will have Aiba find a model UFO, a stuffed Chupacabra, and a one dollar bill. When Date suggests these may be occult stuff, Aiba asks him if it interests him, to which he says "the truth is out there." Aiba points out that the occult is a trending topic in society, so anyone could have this in their Somnium, but she does note how the strange skeleton within the room is different than simply the "occult."
Wine A glass of red wine, named a Bansai-Wine -Spike Chunsoft Original Wine- from 1972. It lies on the table in front of the skeleton.
Lock #2 Only Investigate N/A N/A
Aiba investigates the Bansai-Wine, stating that it is a popular brand on the market. She does note, however, that the red wine is even more red than usual. Date suggests the bottle is a full-bodied red from Bourgogne, France. Aiba questions if that trivia would ever be useful, but Date rebukes by saying it's better to be prepared.
Have a Sip
Suggesting that Aiba take a sip of the wine will instead have her chug the entire bottle, much to Date's surprise. The alcohol seemingly loosens up Aiba, making her giddy and crying over Date's tone with her. He wonders how an A.I. can even get drunk in the first place, complaining that she's an annoying drunk that someone else should take care of.
When Aiba smells the wine, she notes that "the nose is fresh, yet rich. I detect smooth tannins and stone fruits," which Date asks on how she learned these terms. Aiba ignores Date's question, instead wondering why the wine is in his dream in the first place, which he responds by saying he likes "good drinks and better company." She notes that his drinking activities with others never turn out well in the end for him, much to his pain.
Skeleton A full-body skeleton sitting on the sofa of the room, facing the table. Its left eye socket has blood dripping out of it.
Lock #2

(Select Search on Basket)

Investigate N/A N/A
Aiba notes the traces of blood found on the skeleton's eye socket, stating that it is clinging to a small bit of life. Date hopes that his bones stay dead once he passes.
Lock #2

(Select Have a Sip on Wine)

Date suggests that the drunk Aiba start talking with the skeleton. She introduces herself to the skeleton, being courteous to it. When the skeleton "ignores her", she begins harassing the skeleton by calling him a stupid boney man and insulting its mother by saying she's a stupid boney girl. Once she's done, she claims her "disappointment is immeasurable" at having no response.
Lock #2

(Select Kick on Standing Lamp)

Aiba reassures the skeleton that she has no grudges against it, before punching it square in the head. The skull is sent flying, and once it lands, the entire room begins vibrating, as everything in the room that is not lit up by light begins crumbling down. As she wakes up in a room constructed of only the spots that remained unlit before (holes laying on the ground where light used to be), Aiba asks Date if he has an urge for destruction he held back on, which he responds simply that adults need to moderate themselves. The mysterious man from before appears as he walks through the chained door (now lit up by the lamp that fell on the floor), which Date reinforces that he hasn't met him before, simply referring to him as an old man.

This action leads further into unlocking Mental Lock #2, and disables the ability to interact with the previous Mental Lock #2 objects still available.

Gun A gun that came out of the skeleton's skull after it broke to pieces in the fall down. The barrel of the gun is shaped like a key.
Lock #2

(Select Hit on Skeleton)

Pick Up N/A N/A
Aiba picks up the gun, at first worried that it could go off at grabbing it, but once in her hand she comments on how she could "ventilate some crooks" with this "hot magnum". When she asks Date if it reminds him of anyone, he says no.
Aiba wonders why there is a gun in the house, to which Date simply states that anything can happen in a Somnium house that contains a skeleton. Aiba notes that it is common to have a skeleton in the Kyushu area, and that their residents place hand grenades in egg cartons.

This actions allows you to obtain the Gun.

Hidden Item

  • The hidden item is located on the kitchen sink, available after the room is deconstructed near the end of the Somnium.



  • The different occult objects in the basket include a UFO, a Chupacabra, and an American one-dollar bill.
    • UFO is an acronym for an Unidentified Flying Object, usually associated with alien spacecraft.
    • A chupacabra is a Latin-American creature of folklore, directly translating to "goat-sucker", which, as the name suggests, is reported to have drank the blood from rural livestock.
    • The American one-dollar bill has the image of an Egyptian pyramid, with the Eye of Providence situated on the top. The Eye of Providence is usually associated to the urban legend of the Illuminati, the religious organization that oversees governmental faculties around the world.
    • When investigating these objects, Date states "the truth is out there", which is a quote from the American show The X-Files.
  • The Bansai-Wine bottle has the label "Spike Chunsoft Original Wine", in reference to Spike Chunsoft, the company who made AI: THE SOMNIUM FILES. It is currently unknown what the year 1972 refers to, however.
  • When smelling the Wine, Date notes that he likes "good drinks and better company." This could be a reference to his hobby of visiting the bar Marble or the cabaret club Tiefblau.


Kaname DateAibaIris Sagan/A-setOta MatsushitaMizuki OkiuraBossPewterNew Cyclops Killer
Hitomi SaganMayumi MatsushitaRenju OkiuraMamaShoko NadamiSo SejimaMoma KumakuraRohan KumakuraCyclops Serial Killer
#89FalcoBodyguardsTakero MatsushitaManaka IwaiSaito SejimaYakuza AYakuza BNurseReceptionistMermaidTaxi DriverInspector
Chiyoda District: Police Headquarters (Boss's Office; Psync Room; Interrogation Room) • Sunfish Pocket
Koto District: Harbor Warehouse District (Cold Storage Warehouse) • Date Residence
Meguro District: Sagan ResidenceTiefblau
Minato District: Sejima ResidenceKumakura OfficeIkume ShrineLemniscateCentral Hospital
Near Kabasaki District: Bloom ParkOld Chemical PlantMatsushita Diner
Shinjuku District: Golden Yokocho (Marble)
Other: Fuchu City (Fuchu Prison) • Akikawa ValleyOkutama MountainsEitoku High
SINKIN' IN THE BRaiN (Spoiler) • PSYNCIN' IN THE PaiN (Spoiler)
PSYNCIN' IN THE VaiN (Spoiler) • PSYNCIN' IN THE SWaiN (Spoiler)
PSYNCIN' IN THE VILLaiN (Spoiler) • PSYNCIN' IN THE MaiN: 1 (Spoiler)
PSYNCIN' IN THE MaiN: 2 (Spoiler)
Red Route: sigAIsaikAImeikAIsyokubAIrihAI
Yellow Route: syougAIseisAIhiAIsanpAI
Green Route: gumAIjukkAIkikAIjinnAIihAI
Purple Route: keitAIgyoukAIkyuusAIsyuurAIirAIdakkAIkekkAI
Pink Route: kenzAIjutAIkokkAIsousAIhakAIkassAI
Tokyo Metropolitan Police Department (Advanced Brain Investigation Squad) • Ujisaki Family (Kumakura FamilyKumakura Estates) • Secret Society NAIXATLOZForeign Mercenaries
LemniscateSunfish PocketMarbleTiefblauFamiSto8-12Elgorg
Wadjet SystemEvolverLight Synaptic Nerve Connection DeviceDate's CarShovelForgeOdoroki-man ChocolateGeostationary Satellite X00639
Chemical Plant ExplosionOriginal Cyclops Serial KillingsBreak-In at Sagan ResidenceNew Cyclops Serial KillingsIncident at Minato District HighwayDisappearance of Renju OkiuraOperation: Iris Rescue
Full List of Events