Through the Looking Glass, by Kristen999. Gen, team. (ca. 19,000 words)
The story had me on edge the whole time. It is great with the suspense, starting with a slowly growing sense of wrongness and urgency, that gets worse as some of the narrators become more affected. It's not extremely dark though, but a great mix of disturbing elements from their problems (which I don't want to spoil), angst, h/c and the team caring for each other.