When the episode begins, Miles, Julian and Molly are worried because during Keiko's absence, they let her plants die. However, oddly, Keiko is just fine with this and all smiles...until she reveals that she's possessed!!! And, the possessed Keiko promises to murder her host unless Miles helps her! What follows is a really cool version of Keiko--evil, scheming and yet sweet and normal when anyone other than Miles sees her. Personally, I loved this version--especially since 'normal' Keiko was one of the most boring recurring characters on the show. This is not a slam against the actress playing her, Rosilind Chao, as she could only be who the writers let her be. Unfortunately, the possessed Keiko only lasts this episode!
This episode was nice as an introduction to the Pah Wraiths--nasties who would appear in some interesting future episodes. However, the episode also is a bit hard to accept because you would think anyone in this situation would IMMEDIATELY alert the crew as to what was happening--yet Miles O'Brien keeps it to himself throughout the show. Odd to say the least--as are ALL his actions during the episode. Perhaps he just thought the new and improved Keiko was better than the boring old one...like I did.