Riker serves on the Klingon ship I.K.C. Pagh in an officer-exchange program. A parasite eats away at their hull and the Klingons think the Enterprise attacked them. Riker's loyalties are put to the test when the Klingons decide to destroy the Enterprise.

Diana Muldaur (Dr. Katherine Pulaski)
John Putch (Ensign Mendon)
Christopher Collins (Captain Kargan)
Brian Thompson (Lieutenant Klag)

Colm Meaney (Chief O'Brien)
Peter Parros (Tactical Officer)
Laura Drake (Vekma)

• I.K.C. = Imperial Klingon Cruiser.
  
• John Putch also played a Benzite in the 1st season episode "Coming of Age". In that episode, Mordock competed for Starfleet Academy entrance. Lt. Chang congratulated him on being the first Benzite in Starfleet. If Mendon has the rank of Ensign, then he would have been at the Academy prior to Mordock.
  
• This episode had a 12.2 rating, the highest rated TNG episode at this time.
  
• Troi does not appear in this episode, nor does La Forge (this is the first episode in which LeVar Burton does not appear).