Sans' Workshop

Sans himself has a lot to do with this.Straight from the game's data, take a look...\E1* wait a second./\E1* that look on your& face while i was& talking.../\E2* you've already heard& my spiel^1, haven't you?/\E3* i suspected something& like this./\E3* you're always acting& like you know what's& going to happen./\E1* like you've seen it& all before./\E3* so..^1.&* i have a request for& you./\W*\E1 i kind of have a& \Ysecret codeword\W & that only i know./\E0* so i know if someone& tells it to me.../\E1* they'll have to be a& time traveller./\E2* crazy^1, right?/\E1* anyway^1, here it is.../\E3* (whisper^1, whisper)/\E2* i'm counting on you to& come back here and& tell me that./\E1* see you later./%%\E1* huh^1?&* do you have something& to say to me?/\E2* what^1? a codeword^1?&* can you speak a& little louder?/* did you.../\E2* ... just say "i'm a& stupid doodoo butt?"/\E1* wow^1.&* i can't believe you& would say that./\E3* not only is that& completely infantile.../\E2* but it's also my& secret codeword./\E3* that^1, however^1, isn't& good enough./\W*\E1 what you need is the& \Ysecret\W secret codeword./\E2* it's only for people& that know the secret& codeword./\E0* anyway^1, here it is.../\E4* (whimsper^1, whimsper).../\E2* ... just say "i'm the& legendary fartmaster?"/\E1* wow./\E1* that's..^1. uh..^1.&* really childish./\E2* why would you think& that was a secret& secret codeword?/\E1* whoever told you that& is a dirty liar./\E2* i don't have a secret& secret codeword./\E3* however./\E2* i do have a secret& secret triple-secret& codeword./\E1* which you just said./\E2* so^1, i guess you're& qualified./\E2* here's the key to my& room./\E3* it's time.../* you learned the truth./* (When you looked^1, the key was& already on your keychain.)/%%\E1* huh^1?&* triple secret codeword?/\E2* nah^1, i'm out of& material./* (You felt something on your& keychain.)/%%sansfsansk\E0* heya./To gain access to Sans' secret Workshop, you need to be at the end of a True Pacifist run, before the final corridor where Sans gives your lecture. Let Sans explain EXP and Love to you and then reload your save repeatedly. He'll recognise your time travelling powers and give you a key to his room. Once you've entered his room, walk around and trigger a cutscene. Once you're done with this, check Sans' drawers and you'll find a Silver Key. Once you've done this, go behind the left side of their house and you'll find a door that you can unlock. Inside will be some kind of Machine behind a curtain, as well as some drawers filled with blueprints and one containing 'A photograph of you and Sans with all your friends, and Sans with some other people you don't recognise.' The blueprints are written in what the game refers to 'Strange Symbols. Or it could just be the handwriting.' This could potentially poke at Gaster having built the strange machine, and the 'Strange Symbols' being Wingdings.Thank you to Meido Grempy for recording the footage.People have theorised that this machine behind the curtains is some kind of Time Machine, which would perhaps explain Sans' ability to warp around at random (Doggo claims he doesn't like Sans because he travels without moving). It's also worth noting that during the Genocide run with Sans, he talks about how he's been monitoring the timelines for anomalies, and also mentions an 'Us'. This further deepens his potential connection to Gaster.