The Enterprise is ordered to proceed to an emergency rendezvous to collect a special envoy who is traveling from Starbase 153 to meet them. They are given no information about the nature of the emergency, just that they will be briefed by the emissary on arrival. She is K'Ehleyr, a Klingon who has been sent to deal with a Klingon warship - the T'Ong - that has been found in deep space with a crew in long-term stasis. They predate the current peaceful coexistence between the Federation and the Klingon Empire and as far as they are concerned, the Klingon warriors aboard the T'Ong are still at war with the humans. Worf has a solution to dealing with with the warriors. Meanwhile, it appears that K'Ehleyr - who is half-human - has a history and perhaps at one time a romance, with Lieutenant Worf.