The Enterprise is ordered to divert from their current course to just outside a recently colonized system. When they arrive, Admiral Gromek tells Picard that a special emissary will be arriving shortly, who will give them the mission briefing, but says no more. When the emissary arrives (in a Class-8 probe, of all things, so as to arrive quickly), the crew revives K'Ehleyr, a half-human, half-Klingon female. As she enters to begin the briefing, she recognizes and greets Worf, saying "so this is where you've been hiding-I told you we'd meet again."

At the briefing, she tells them of a Klingon ship, the T'Ong, which set out on a mission with the crew in suspended animation 75 years ago, while the Klingons and Federation were still at war, and that the nearest Klingon ship is 48 hours behind them, which may be too late. Their task is to prevent the crew from awakening, if possible, and to destroy the ship, if not. Picard, not willing to simply destroy them out of hand, puts K'Ehleyr and Worf to work on finding other options. Unfortunately, the two don't interact very well. K'Ehleyr is anxious to discuss their aborted love affair of six years earlier, but Worf is all business. He searches for their mission and talks of alternatives, but K'Ehleyr says there are no alternatives. Eventually, K'Ehleyr storms to her quarters and smashes a table in frustration.

Later, on Troi's advice, she goes to exercise on the holodeck, and ends up using Worf's violent calisthenics program. As she finishes, Worf enters, and when provoked, increases the simulation to "Level Two". Both fight, then have a rather passionate encounter. When K'Ehleyr later remarks that Worf always was loath to speak what's on his mind, Worf responds by saying "no longer" and beginning to recite the Klingon oath of marriage. K'Ehleyr refuses to take the oath, dishonoring what to Worf are sacred traditions. Meanwhile, they approach the general vicinity of the T'Ong, still with no options but to destroy the ship if the crew has already awakened.

They quickly find the crew has awakened, when it fires on them and then cloaks. Suddenly, Worf has an idea, and it is quickly implemented: when Captain K'Temok of the T'Ong answers the hail, he sees "Captain" Worf of the Enterprise informing him the war is long over and ordering them to drop their shields. K'Temok initially refuses, but then agrees when he sees Worf will destroy the T'Ong if not obeyed. K'Ehleyr prepares to beam over to the T'Ong to begin assimilating them into this century. She confesses to Worf that she was tempted to take the oath, and jibes that next time, "I won't be so easy to get rid of." Worf beams her off, saying "I will not be complete without you."