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The True Laboratory is a private section of Alphys's Lab that can only be found and entered during the True Pacifist Route.


  • This area is the point of no return for the True Pacifist Route. Upon entering the True Lab, the True Pacifist Route can no longer be aborted, and most of the Underground becomes inaccessible until the epilogue.
  • The amalgamates are introduced, along with the details about Alphys's experiments with human SOULs in an attempt to find a way to destroy the Barrier.
  • The screens on the walls explain the concept of determination in great detail, including its effects on both humans and monsters and how it was extracted and used by Alphys in her experiments.
    • It is also revealed that SOULs cannot be artificially created, contrary to what Alphys told King Asgore[1] in order to get her job as a royal scientist.
    • A few of the screens also reveal how Flowey came to be.
  • The information that can be gathered in this location provides an insight on Alphys's personality and some of the causes of her anxiety, insecurity and lack of self-esteem, as well as some detail about how she and Mettaton began to grow more distant.
    • This area also features a set of VHS tapes providing more information about the first fallen human and their relation with the Dreemurr family.

Main Story

Neutral Route

When the protagonist first enters Hotland, they are led to believe that the elevator leading to the True Lab is a toilet, due to Alphys's dialogue.

In some Neutral endings,[2] it is implied Alphys commits suicide here.

In the near-genocide Neutral Route ending, Alphys talks for most of the endgame phone call. She says that, despite having to reveal the truth about herself to everyone, people still treat her like a hero.

True Pacifist Route

Hey. Thanks for your help back there. You guys... Your support means a lot to me. But... As difficult as it is to say this... You guys alone can't magically make my own problems go away. I want to be a better person. I don't want to be afraid anymore. And for that to happen, I have to be able to face my own mistakes. I'm going to start doing that now. I want to be clear. This isn't anyone else's problem but mine. But if you don't ever hear from me again... If you want to know "the truth." Enter the door to the north of this note. You all at least deserve to know what I did.

Alphys's Note, before entering the True Lab

The entrance to the True Lab, initially disguised as a bathroom.

After the protagonist has completed the date with Alphys by giving her Undyne's Letter, Papyrus calls the protagonist and strongly recommends that they meet Alphys at her lab. When the protagonist arrives at the Lab, there is a note in front of the previously locked door, which now opens upon approaching.

Battle against Lemon Bread

After entering the door, the protagonist rides an elevator that malfunctions and crashes. Once the protagonist enters and opens the elevator door, they cannot return to the rest of the Underground as they are locked in the True Lab. The protagonist traverses the True Laboratory where they find several Lab Entries, Amalgamates, and four keys which give access to the power supply to restart the elevator.

In the True Lab, the protagonist learns about how Alphys experimented with determination, SOULs, fallen monsters, and Golden Flowers. It is here that the protagonist learns about the term "fallen down", which refers to a comatose state that monsters fall under before turning to dust (this term was previously mentioned in one of Mettaton's diaries in his house). While working with Determination, Alphys resurrected monsters who had "fallen down" such as Shyren's sister and Snowdrake's Mother, who as a result soon melted into Amalgamates. The protagonist also discovers that Alphys attempted to create a soulless vessel from a Golden Flower; the vessel is heavily implied to be Flowey. Alphys's lab entries provide backstory on her experiments and are found throughout the True Lab.

The DT Extraction Machine

While exploring the Lab, the protagonist encounters a strange machine. This machine is the DT Extraction Machine, which Alphys used to extract determination from the six previously captured human SOULs. The protagonist also finds several VHS tapes that lack video motion but retain their audio. They document conversations between Toriel and Asgore, and Asriel and the first human. These tapes imply that the fallen human possessed darker tendencies: they attempted suicide as part of a plan to combine their SOUL with Asriel's to pass through the barrier, and that Asriel reluctantly helped them carry out their plan. The VHS TV in this room resembles the TV that projects Photoshop Flowey's face.

The generator that powers the elevator up to New Home

The protagonist then restores power to the elevator. Moments later, Amalgamates surround them. Alphys rushes into the room, saves the protagonist, and states that Amalgamates can get violent when not fed. After the Amalgamates leave the room, Alphys thanks the protagonist for the help and mentions that it is not the Amalgamates which would have made her "disappear" but instead something cowardly which she might do. This cowardly act may be suicide considering that some neutral endings tell of Alphys disappearing.[2]

As the protagonist makes their way to the elevator, the exit cuts off, and a voice is heard congratulating the protagonist. The elevator then leaves the protagonist in New Home, with the elevator down to the CORE sealed off with vines so that the protagonist cannot leave. This indicates that the requirements have been met for the True Pacifist Ending.

Genocide Route

Upon defeat, Undyne the Undying informs the protagonist that Alphys has evacuated the majority of the remaining monsters someplace safe, heavily implied to be the True Lab.

In the Genocide ending, the evacuation was pointless, as the first human destroys the entire world and ends the timeline.


A hallway in the True Lab

In contrast to the bright, sterile color scheme of the Lab, the True Lab is grimy, dark, and fog-filled. It has a dark green celeste color scheme and an unsettling atmosphere. Assorted objects fill the area, including beds, sinks, refrigerators, wall fans, mirrors, and Golden Flowers. There is a vending machine that dispenses Popato Chisps near the power room door.

There are four colored keys scattered throughout the True Lab. The slots that the keys are inserted into, save for the yellow key, are housed in small, square rooms. These rooms contain hints as to how to obtain the key that belongs in the slot.

Entry Elevator to Power Room Door

After exiting the elevator, the protagonist finds themself in a small room. After walking a short distance, the elevator door closes and is unable to be reopened. The room has a pathway to the right that leads to a horizontal hallway with entries 1, 2, 3, and 5 along the wall. The hallway veers upwards into the room with the power room door. The layout of this room is similar to that of the lobby of the CORE, with the power room door to the north and two upwards paths to the left and to the right. The left path leads to the slot for the red key, and the right path leads to a door that can only be unlocked by using the red key. The power room door is locked and can only be opened after all four keys are used. This room also contains two fake plants, a vending machine that dispenses Popato Chisps, and a partially readable note from Alphys stating the power room door must be opened to restore power to the elevator.

Power Room Door to Red Key Slot

The upwards path to the left veers to the left into a horizontal hallway that contains entry 6 and a foggy room that contains entry 9. In this room is a line of three operating tables that are revealed to be "sticky" upon inspection. Further into the room is a doorway leading to the red key slot, and next to the doorway is a line of three sinks. Turning on the three sinks (or turning one off and back on again) triggers an encounter with the Memoryheads. Upon defeat, the Memoryheads drop the red key, which is used to unlock the door to the right of the power room door.

Red Key Door to Bedroom

Entering through the red key door leads to a hallway that veers to the right. Entries 12 and 13 are along the wall. This hallway leads to the bedroom, which contains a dog food bowl, four fake plants, a broken clock, and nine beds. The bottom left bed can be slept in, and the middle right bed contains the yellow key. The northernmost part of the bedroom contains a doorway, a SAVE Point, and entry 14, and the eastern path leads to the blue key slot.

Bedroom to Fan Room

The doorway to the north of the bedroom leads to a long, horizontal hallway that spans to the left and right side of the pathway. Going to the right leads to the fan room, which contains entry 11. The area is initially clouded by fog, with white particles hovering above the floor. There is a switch at the end of the room that, when pressed, turns on the fans that blow the fog away, leaving behind the white particles. The white particles converge and form Endogeny, who slowly approaches the protagonist. The protagonist can walk to Endogeny to initiate the battle.

Bedroom to DT Extraction Machine

True Lab location shower room.png

Along the wall to the left of the bedroom pathway are entries 15 and 16. Near the end of the hallway is a doorway leading to a vertical hallway with a bathtub. The bathtub is covered by a curtain, and the silhouette of an amalgamate can be seen behind it. Approaching the bathtub, the protagonist walks slower than normal, and the amalgamate moves faster the closer they get. Upon opening the curtain, the amalgamate disappears, and the green key is left behind. To the west is a large room containing the DT Extraction Machine, which is inactive. North of this room is a room with a TV and five VHS tapes, entry 4, and the yellow key slot. The pathway to the other side of the room with the DT Extraction Machine is blocked by a SAVE Point, which transforms into Lemon Bread upon inspection.

DT Extraction Machine to Green Key Slot

Past the DT Extraction Machine is a room containing entries 19, 20, and 21. This room contains five fridges spread evenly along the room. The fridges are either empty or contain samples of some sort. The third fridge shakes periodically, while the fifth fridge is revealed to be a disguise for Snowdrake's Mother upon inspection. If the fan switch has not been turned on, the room is shrouded in a thick fog which prevents the fridges from being seen, and their descriptions upon inspection are mere conjectures. Snowdrake's Mother drops the blue key upon defeat. In the adjoining room is the slot for the green key.

Bedroom to Blue Key Slot

Golden Flowers along a table in the room where Reaper Bird is fought

Returning to the bedroom and traveling through the right pathway, the protagonist enters a horizontal room with mirrors along the northern wall and a table with Golden Flowers along the southern wall. Between the first three mirrors are entries 7 and 10. While attempting to travel across the room, the protagonist is stopped by a random encounter indicator, which transforms into Reaper Bird. At the end of the room is a room with the blue key slot.

Power Room Door to Power Room

After collecting all four keys, the power room door is unlocked. Entering through the door leads to an elevator that is connected with a western pathway. Going through the pathway leads to a horizontal hallway with blank screens along the wall. At the end of this hallway is a doorway leading to the power room. The Power Room contains a generator which has a red, heart-shaped figure on its front. After turning on the power, several amalgamates approach and surround the protagonist, and Alphys rushes in and bails them out. The protagonist then leaves the room and travels back through the hallway. The blank screens on the wall turn on to reveal entries 8 and 18. After returning to the elevator, the western and southern pathways are cut off, and the protagonist is then thrust into New Home.

Lab Entries

Lab Entries can be found on the numerous panels that can be seen throughout the lab. The entries are numbered from 1 to 21, but there is no 17th entry. In the game data, there are two 17th lab entries which cannot be accessed in normal gameplay; one of them is completely in Wingdings and presumed to have been written by W. D. Gaster.[3] Most of the entries contain extensive information about Alphys's experimentation concerning SOULs, Determination, monsters, and Flowey.

  • This is it... Time to do what the King has asked me to do.
  • I will create the power to free us all.
  • I will unleash the power of the SOUL.
  • The barrier is locked by SOUL power..
  • Unfortunately, this power cannot be recreated artificially.
  • SOUL power can only be derived from what was once living.
  • So, to create more, we will have to use what we have now...
  • The SOULs of monsters.
  • But extracting a SOUL from a living monster would require incredible power...
  • Besides being impractical, doing so would instantly destroy the SOUL's host.
  • And, unlike the persistent SOULs of humans... The SOULs of most monsters disappear immediately upon death.
  • If only I could make a monster's SOUL last...
  • I've been researching humans to see if I can find any info about their SOULS.
  • I ended up snooping around the castle... And found these weird tapes.
  • I don't feel like ASGORE's watched them...
  • I don't think he should.
  • I've done it.
  • Using the blueprints, I've extracted it from the human SOULs.
  • I believe this is what gives their SOULs the strength to persist after death.
  • The will to keep living... The resolve to change fate.
  • Let's call this power...
  • "Determination."
  • ASGORE asked everyone outside the city for monsters that had "fallen down."
  • Their bodies came in today.
  • They're still comatose... And soon, they'll all turn into dust.
  • But what happens if I inject "determination" into them? If their SOULS persist after they perish, then...
  • Freedom might be closer than we all thought.
  • We'll need a vessel to wield the monster SOULs when the time comes.
  • After all, a monster cannot absorb the SOULs of other monsters.
  • Just as a human cannot absorb a human SOUL...
  • So then...
  • What about something that's neither human nor monster?
  • I've chosen a candidate.
  • I haven't told ASGORE yet, because I want to surprise him with it...
  • In the center of his garden, there's something special.
  • The first golden flower, that grew before all the others.
  • The flower from the outside world.
  • It appeared just before the queen left.
  • I wonder...
  • What happens when something without a SOUL gains the will to live?
  • things aren't going well.
  • none of the bodies have turned into dust, so I can't get the SOULs.
  • i told the families that i would give them the dust back for the funerals.
  • people are starting to ask me what's happening.
  • what do i do?
  • experiments on the vessel are a failure.
  • it doesn't seem to be any different from the control cases.
  • whatever. they're a hassle to work with anyway.
  • the seeds just stick to you, and won't let go...
  • now that mettaton's made it big, he never talks to me anymore.
  • ... except to ask when i'm going to finish his body.
  • but i'm afraid if i finish his body, he won't need me anymore...
  • then we'll never be friends ever again.
  • ... not to mention, every time i try to work on it, i just get really sweaty...
  • nothing is happening.
  • i don't know what to do.
  • i'll just keep injecting everything with "determination."
  • i want this to work.
  • one of the bodies opened its eyes.
  • Everyone that had fallen down...
  • ... has woken up.
  • They're all walking around and talking like nothing is wrong.
  • I thought they were goners...?
  • Seems like this research was a dead end...
  • But at least we got a happy ending out of it...?
  • I sent the SOULS back to ASGORE, returned the vessel to his garden...
  • And I called all of the families and told them everyone's alive.
  • I'll send everyone back tomorrow. :)
  • no No NO NO NO NO NO
ENTRY NUMBER 17 (inaccessible in-game)
  • monsters' physical forms can't handle "determination" like humans' can.
  • with too much determination, our bodies begin to break down.
  • everyone's melted together...

Gaster's Entry Number Seventeen (note Wingdings font)

  • the flower's gone.
  • the families keep calling me to ask when everyone is coming home.
  • what am i supposed to say?
  • i don't even answer the phone anymore.
  • ASGORE left me five messages today.
  • four about everyone being angry
  • one about this cute teacup he found that looks like me
  • thanks asgore.

VHS Tapes

The room with the TV, entry number 4, and the yellow-colored switch.

The five VHS tapes can be found in the room with the TV, which is north of the room with the DT Extraction Machine. They contain recordings of Asriel, his family and the Fallen Child interacting. However, these do not have any visual content.

Tape 1
  • (Toriel) Pssst. Gorey, wake up.
  • (Asgore) Mmm? What is it, dear? ... er, and why do you have that video camera?
  • (Toriel) Shush! I want to get your reaction.
  • Gorey, dearest. What is my favorite vegetable?
  • (Asgore) Hmmm... Carrots, right?
  • (Toriel) No no no! My favorite vegetable is...
  • Eda-MOM-e.
  • ... get it???
  • (Asgore) ... Go back to bed, dear.
  • (Toriel) No no!! Not yet! Hee hee hee.
  • Now, If I were a dog, what breed of dog would I be?
  • (Asgore) Hmmm... I don't know, honey. What kind of dog would you be?
  • (Toriel) I would be...
  • (Asgore) Hohoho!
  • You sure are excited to have this child.
  • You know, if you keep making jokes like this...
  • One day, you could be...
  • ... a famous MOMedian.
  • (Toriel) ... Well, I am going to bed.
  • (Asgore) Hey! Come on Tori! That one was funny!
  • (Toriel) Hahaha, I know. I am just teasing you.
  • Goodnight, dear.
  • (Asgore) Goodnight, honey.
  • (Toriel) ... Oh dear, perhaps it is too dark in here for the video to come out.
Tape 2
  • (Asriel) Okay, <Name>, are you ready?
  • Do your creepy face!
  • AHHHHH!! Hee hee hee!
  • Oh! Wait! I had the lens cap on...
  • What!? You're not gonna do it again...?
  • Come on, quit tricking me! Haha!
Tape 3
  • (Asriel) Howdy, <Name>! Smile for the camera!
  • Ha, this time I got YOU! I left the cap on... ON PURPOSE!
  • Now you're smiling for noooo reason! Hee hee hee.
  • What? Oh, yeah, I remember.
  • When we tried to make butterscotch pie for Dad, right?
  • The recipe asked for cups of butter...
  • But we accidentally put in buttercups instead.
  • Yeah! Those flowers got him really sick.
  • I felt so bad. We made Mom really upset.
  • I should have laughed it off, like you did...
  • Um, anyway, where are you going with this?
  • Huh? Turn off the camera...? OK.
Tape 4
  • (Asriel) I... I don't like this idea, <Name>.
  • Wh.. what? N-no, I'm not...
  • ... big kids don't cry.
  • Yeah, you're right.
  • No! I'd never doubt you, <Name>. Never!
  • Y... yeah! We'll be strong! We'll free everyone.
  • I'll go get the flowers.
Tape 5
  • (Toriel) <Name>... Can you hear me? We want you to wake up...
  • (Asgore) <Name>! You have to stay determined!
  • You can't give up! You are the future of humans and monsters...
  • (Asriel) ... Psst... <Name>... Please... Wake up...
  • I don't like this plan anymore. I... I...
  • ... no, I said... I said I'd never doubt you.
  • Six, right? We just have to get six...
  • And we'll do it together, right?


  • There is a known glitch in which the Blue Key cannot be seen after being dropped but can still be picked up.
  • The teacup mentioned in Entry Number 20 can be found in Alphys's lab, sitting on her desk.
  • The DT Extraction Machine also heavily resembles a Cervine (Deer) skull, the same way Sans's Gaster Blasters resemble Canid (Dog) skulls, and Asriel's skull during the final battle resembles a Capra (Goat) skull.
  • In the room with the beds, laying down on the bottom left one for a short while will cause an amalgamate to appear and extend out an arm to pull up the cover over the protagonist, then pat their head before disappearing.
True Lab screenshot shape of a man.png
  • If the protagonist enters the refrigerator room without turning on the ventilation first, the fog will change the protagonist’s interactions with the environment to vague assumptions. The refrigerators will be described as "It's some sort of cold, rectangular object." Other observations are:
    • "There's something here... It feels like it's breathing."
    • "There’s something here... It feels like a tree, ripe with delicious fruit."
    • "There's something here... It feels warm, and moist."
    • "There’s something here... Something in the shape of a man."
  • The screens for Entry Numbers 8 and 18 display a red smile instead of green lines like the other entries, possibly because they tell of how Alphys created Flowey, and Flowey disguises his dark intentions with an innocent smile.
  • If the protagonist has Popato Chisps in their inventory, Alphys says in the power room Amalgamates probably smelled the chisps in their inventory.
  • It is speculated that the True Lab is where Alphys evacuates everybody to during the Genocide Route, as Alphys mentions during the Near Genocide Neutral ending that doing it would cause everyone to find out the truth about her.[4]
  • If the player's controller is disconnected in the Xbox version while in the True Lab, under the "No Controller Connected" message is a list of other human body parts that are said to not be connected.[5]


  1. Bratty: "So Alphys has always, like..."
    Catty: "Thought ASGORE is a SUPER cutie."
    Bratty: "So, like, I'm pretty sure she..."
    Catty: "Made Mettaton to, like, totally impress him."
    Bratty: "A robot with a SOUL..."
    Catty: "That's, like, SUPER relevant to his hobbies!"
    - Bratty and Catty
  2. 2.0 2.1 Betrayed Undyne Ending (Mettaton dead) and the Mettaton Ending
  3. By changing your room number in both your save0 and your .ini file to 264, a set of wingdings will appear. - W.D Gaster: Undertale's Last Secret (Mistress Spitfire, September 18, 2015.) Steam Community.
  4. Even if it meant everybody would... Have to learn the truth about me. - Alphys
  5. I just find out that if you disconnect your controller in the "true laboratory" of alphys in the Xbox version, this shows up - u/MorsaRika on Reddit, March 18, 2021.