The violin plays a melody using only the notes F, C, A, and G, which we determined by ear and used to unlock the floor.

4:22The violin output needs to be >> [music] >> a string containing A B >> Since only four >> F and G. Is it only uses A C F and G? >> F and G >> A F >> Oh, you're right. It's only >> F C >> [music] >> No, so I think it would be F C A G. >> [music] >> Um Why Why does mine say it's not the

5:14uh What is the expected format? >> Oh, you have input. Maybe you have to disconnect that input. Cuz right now I only have the output and then you can play it. Oh, but and you're also connected to the chessboard. I think you want to be connected to the violin. >> That's why. I think I I You can't play music on a chessboard. >> [laughter] >> Okay, hold on.

5:37>> Okay, I'm I'm holding. I'm holding. >> A B F G. Let me just hear what the notes are on there. Okay. >> So, it starts with F. >> Okay, I got it. >> Yes. Nice job, Scott. >> Thank you. Let's just put those ears to use. >> And that unlocks the floor. There's a new clue. It's a map. A subway map. And there's I mean, I think we need to

6:12take note of these cuz these are written absolute I think it's a cipher. They're written all over the the apartment. Like E is V, Q is Z, O is D, K is E. >> Oh. >> And if you look back on his >> B S I >> back on his desk, there's a couple of them. And then all written on written on the walls, there's a couple of them.

6:27My my guess Well, I was going to say Caesar cipher, but probably not cuz I see R goes to S. So, that's just a shift of one. >> What's the main output? Or we don't know that yet. >> Uh there's Well, only one more spot we need to figure out, which is the chessboard. Um >> Okay. I have something interesting here. The butterflies. There's butterfly buttons on the walls,