L's been particularly quiet throughout the explanation. He received a note and is committed to breaking in, but once inside, there's precious little he could do. He could even be a liability, given the dangers that have been related in this strange other world.

"If our mutual acquaintance has been trapped in this Nephele, but his omen has been here in Trench to communicate and assist us... it stands to reason that it could work the other way around, doesn't it? Those of us who are better off remaining behind could at least do that much, and send omens in with the away team."