Plot summary
The Enterprise, under the command of Captain Jean-Luc Picard, rendezvouses with a Federation emissary: K'Ehleyr, a half- Klingon half-human woman who has a history with Lt. Worf. K'Ehleyr informs the command staff that Starfleet has detected a Klingon battlecruiser called the T'Ong, whose crew has been in suspended animation for over 75 years, since the Klingons and the Federation were at war. Its crew are about to awaken, at which point it is feared they will attack the nearest Federation outpost. As the nearest Klingon ship is three days away, the Enterprise is to intercept them instead. Though K'Ehleyr believes that any attempt to reason with the Klingons will fail, and advises that Picard plan to destroy the ship, Picard disagrees and orders the staff to come up with peaceful alternatives.
Picard orders Worf to work with K'Ehleyr over Worf's objections. Worf and his ex-lover have a heated argument, barely managing to concentrate on their task. At Counselor Troi 's suggestion, K'Ehleyr goes to the holodeck to vent her frustrations in one of Worf's hand-to-hand combat simulations. Worf finds her there and joins her, and, stimulated by the battle, they mate. Following tradition, Worf starts the Klingon vow of marriage, but K'Ehleyr refuses to take the vow and storms out.
When the T'Ong is detected, it fires on the Enterprise, cloaks, and moves away. The Enterprise is able to track the older vessel and pursues it. K'Ehleyr urges Picard to let the Klingons die with honor, in battle. However, Worf comes up with another option: Worf and K'Ehleyr, clad in Klingon command uniforms, appear as captain and first officer of the Enterprise, informing Captain K'Temoc of the T'Ong that the war is over and ordering them to surrender. K'Temoc initially refuses, but when Worf, in typical Klingon manner, shows his resolve and threatens to destroy the T'Ong, K'Temoc grudgingly agrees.
K'Ehleyr transports to the T'Ong to begin the process of acclimating the Klingons to life in the 24th century and await the arrival of the Klingon escort. Before departing, she admits to Worf that she was tempted to take the marriage vow with him, and implies that their paths will cross again.
Credits
Adapted from Wikipedia contributors, The Emissary (Star Trek: The Next Generation). Paragraphs and formatting adjusted; illustrations, reference markers, block quotations and non-story material omitted.