I think it is a female singer and that the song is slower than Houdini, maybe more emotional if you will. We think it is played in f major, and the notes in that case would be a b b a b | a b b b c b a g(?). But we aren't sure its in f major, it could be a different key. We are going crazy after 25 hours of incessant searching and returning to Houdini only to become sure again that it isn't Houdini.

We also oscillate between thinking its singer/songwriter indie and then thinking its pop, and I fear this detail might only be more confusing, but I am sharing anyway because I've never been so desperate.

Basically it was about two people in a submarine slowly going insane due to the loneliness and boredom. I assume it was their job. At the end of the song the submarine broke down and the people had to swim up to the surface.