.. Ending the concert

Do you have access to the Control Room?

And you have talked with the Nerd?

He is controlling the show. You should mess with him.

He was quite interested in the Dark Room.

And he is a huge scifi fan.

Get him such a tempting dark room experience that he will leave the controls.

Have you figured out the Dark Room?

And you have the blueprint in your mobile?

Great, now upload the blueprint into the darkroom (Use your phone on the touchscreen after clicking "upload".) .

Have fun with Vanya in DarkRoom III room. Go tell the Nerd that Vanya is waiting for him.

Use the Great Console to end the concert.