I don't want plot specifics, just the episode title. If I have the box set it's in, I'll be watching it soon enough. I actually had a whole list of episodes I wanted identified, but through Yahoo! searches, I've been able to wittle it down. This one continues to elude me. Perhaps because what I'm remembering was probably a minor element. I remember something about the Enterprise transporting a delegation (or two) of aliens somewhere. What I remember is one of the labs being converted to an aquatic environment, or maybe the composition of the atmosphere in the lab was changed. I'm picturing purple smoke. I think there may even be a crisis when the environmental containment starts breaking down, or something. This is definitely not the season one episode with the snake/dog delegations. Any clues from that? Also, another one: there is some kind of energy anomaly in the ship that at one point manifests itself as a distortion on one of the shuttle bay walls.