A Klingon ship blasts through the wormhole and explodes, but not before an injured Klingon, shrouded in a strange violet light, transports to the station and dies. Soon everyone on board begins to undergo bizarre personality changes: Bashir becomes cold and calculating; O'Brien turns power-hungry and suspicious; Dax grows dreamy and distant; and Major Kira plots to overthrow Sisko. The only one who seems to be unaffected is Odo. While he searches for clues to the crew's mysterious behavior, the senior officers begin to choose sides as the battle for control of the station rages.

Tom Towles (the Klingon)
Jeff Pruitt (Ensign)
Stephen Parr (Valerian)
Randy Pflug (Guard)