The sonic cannon idea is... really, something he needs to talk to the Apollo kids about, but that idea gets squashed immediately. It's just one of those horrible, inappopriate thoughts that floats up from the subconscious.

He does know what an airlock is, and that there's no oxygen in space. He wishes he didn't, in the context of this moment. Tim's lucky... Nico's worried that his friends might not be.

"He was dying," Nico says quietly. He's not going to pretend that he wasn't. "It feels - wrong, now. Like someone paused the movie." Like Leo did, but at least this time everyone won't think Tim's dead for months and he's just hanging out on an island with Calypso.