Kirk goes below deck to work on the deflector relays, but the ribbon suddenly strikes the starship, tearing a large gash through the hull and leaving only debris where Kirk was working. Scotty and Chekov stare out into space, bewildered by the sudden loss of their friend.

Seventy-eight years later, in 2371, the crew of the U.S.S. Enterprise NCC-1701-D join together on the holodeck for a ceremony to promote Lt. Worf — a Klingon officer — to the rank of Lieutenant Commander. The ceremony is conducted using a 19th-century sailing ship and corresponding uniforms. The merriment is suddenly interrupted, however, when Picard receives an urgent personal message. Suddenly depressed, Picard leaves the festivities to contemplate in privacy.

Sent to the Amargosa Observatory to investigate a distress call, the U.S.S. Enterprise finds two dead Romulans and five humans left alive after a mysterious and brutal attack. One of these survivors is a Dr. Tolian Soran. Data and La Forge later return to the starship's laboratory and find traces of a volatile explosive which Soran has secretly concealed in the lab. While Data watches in abject terror, Soran kidnaps La Forge, taking him to a cloaked Klingon ship. When questioning La Forge proves unsuccessful, Soran releases the starship officer — after modifying his VISOR to transmit its signals back to the Klingon vessel.

Soran then fires a trilithium probe into the sun, which causes an incredible shock wave. The Klingon ship, on which he is a passenger, is commanded by the Klingon Duras sisters. In exchange for the formula for Soran's trilithium explosive, they have agreed to take him to the planet Veridian III, where he wants to conduct another solar implosion.

On board the U.S.S. Enterprise, Picard learns that Soran is 300 years old and, like Guinan, a survivor of the El-Aurian incident that killed Captain Kirk. In an effort to understand what is happening, Picard finally goes to Guinan. She tells him that the energy ribbon, called the Nexus, is a temporal anomaly moving through space. To anyone or anything inside the Nexus, linear time has no meaning and a person can experience anything that he or she desires. There is an overpowering feeling of joy so addictive, that once there, no one wants to leave. Soran is desperate to return to the Nexus and recreate that joy with the family he lost when his world was assimilated by the Borg.....