While on a routine exploration of a new planet, Voyager responds to the distress calls of a Kazon warship. Upon investigation, they find the Kazon ship hobbled by an accident caused by Federation technology...a clear signal that Voyager may be carrying a traitor.

Josh Clark (Lt. Joe Carey)
Martha Hackett (Ensign Seska)
Anthony DeLongis (Maje Culluh)

• The crew learns Seska is not a Bajoran, but actually a Cardassian spy who was surgically altered to infiltrate the Maquis, and that she has been secretly working with the Kazon.
  
• This is the last appearance of minor character Lt. Carey (the assistant chief engineer), though he is referred to in later episodes, until the fifth season episode "Relativity".