Part I On the holodeck,
Lt. Commander Data plays a game of poker with holographic representations of Sir
Isaac Newton,
Albert Einstein, and
Stephen Hawking. Data explains to Newton that the game is an experiment for understanding "how three of history's greatest minds would interact" in such a setting. He suspends the program when a red alert is issued from the bridge. The responds to a distress call from a Starfleet outpost. Riker, Worf, Data and a security guard form an away team and they find the crew of the outpost dead. They are suddenly attacked by a group of
Borg, who kill the
"red shirt" security guard. Riker notices that, in contrast to previous encounters, the Borg are armed with energy weapons and refer to each other as individuals. Data experiences anger while fighting a Borg and breaks the Borg's neck. One Borg begins talking to himself about the nature of the away team members and appears to signal a withdrawal when he sees that Data is an android. Meanwhile, in orbit, an unidentified ship fires on the
Enterprise, which returns fire. The alien ship beams up the remaining Borg from the outpost and flees, with the
Enterprise in pursuit. The Borg ship suddenly enters a vortex and disappears. On the planet surface, Riker asks Data what happened, but Data can only explain that he felt anger. The away team is beamed back on board and Admiral Nechayev arrives to take command of the situation. She reprimands
Picard for not destroying the Borg when he had the chance ("
I, Borg") and orders him to do so if another opportunity presents itself. Data continues to try to understand what caused his behavior on the outpost. He tries to experience emotion again through simulations of the event, but does not succeed. The Borg ship reappears and attacks another outpost. The
Enterprise is once again the nearest ship, which makes Picard suspicious, since there are now several Starfleet vessels patrolling the area. The Borg ship reenters the vortex and disappears when the
Enterprise intercepts; the
Enterprise is caught in its wake and follows. When the ships have exited the vortex the Borg attack the
Enterprise, beaming drones on to the bridge. After a brief fire fight, one drone is killed and another wounded, but the distraction allows the Borg ship to escape. This, too, is unusual Borg behavior, since they had always reclaimed their drones, whether alive or dead. The crew discover that the vortex takes them from one star system to another almost instantaneously. They do not know how it is activated, though, so they are unable to return to Federation space. Data is sent to speak with the captured Borg in an attempt to gather intelligence, but the drone manipulates Data into releasing him and they escape together in a shuttlecraft. Before the
Enterprise can catch the shuttle it disappears into a conduit. The crew have learned how the conduits are activated and the
Enterprise gives chase, tracking the shuttlecraft to a planet. An away team finds no trace of Data or the Borg, and something in the planet's atmosphere is blocking their sensors, so Picard decides to conduct a ground search utilising nearly the whole crew of the
Enterprise. Only a skeleton crew now remain on board under the command of
Dr. Crusher. Searching the planet, Picard,
Troi, a security officer and
La Forge enter a building and are surrounded by noisy Borg. Their leader, appearing on a platform, resembles Data but Troi recognizes that it is Data's brother
Lore. Data appears alongside Lore and announces that together they will destroy the Federation.
Part II Lore has discovered a way to give Data emotions and has turned him against
the Federation. Lore plans to lead the breakaway group of Borg to destroy all organic life, believing that Lore and Data are perfect life forms. Picard, Troi, and La Forge are taken captive. Lore orders La Forge's
VISOR removed. La Forge tells Picard and Troi that the VISOR enabled him to see a
carrier wave being beamed from Lore to Data and they surmise that this is the source of Data's emotions and Lore's control over him. In orbit, the Borg ship is detected and Dr. Crusher, acting as captain, orders the away teams to be beamed back aboard from the planet. There is not enough time to retrieve them all and 47 crew members remain on the planet. Riker orders Crusher to leave the area and come back only when it is safe, since the rogue Borg vessel has detected the
Enterprise. Rather than leave the system, Crusher orders the crew to take the ship into the star. Using the technology developed by
Ferengi scientist
Dr. Reyga, they modify the shields to allow them to get closer to the star than the Borg can. They use the ship's phasers to trigger an eruption on the star's surface which destroys the Borg ship. On the planet, Lore orders Data to perform an experiment on La Forge's brain – an irreversible procedure with a "60% chance" of being lethal. La Forge pleads with Data, who ignores him and continues setting up the process. In their prison cell, the away team constructs a device which they believe will reactivate Data's morality
subroutines, hoping that he will question his unethical actions and Lore's intentions.
Riker and
Worf encounter
Hugh, who tells them that Lore is the leader of this Borg group. He says that at one time Lore's help was necessary after the Collective disconnected the group because of Hugh's individuality spreading, but that he has destroyed many Borg through brutal
experimentation. Hugh's group are "rebel" Borg, attempting to remove Lore from power. The away team manages to reactivate Data's ethical programming just as he is about to start the irreversible part of the experiment. La Forge pleads with Data, asking him to check his conscience. Data falters, claims that there are anomalies in the experiment and postpones it. Lore begins to doubt Data's devotion and attempts to strengthen control by threatening to remove the emotions he has provided. Data appears to be subservient, but Lore remains suspicious, and orders Data to prove his loyalty by killing Picard. Data refuses, as the rebooting of his morality subroutines is complete. Two Borg seize Data and Lore is about to execute him, when Riker and Worf arrive, accompanied by Hugh and some of the rebel Borg. A battle commences and Lore flees, pursued by Data. In their ensuing confrontation, Lore attempts to talk Data into escaping with him. When Data is unswayed, Lore attacks Data, but Data shoots him with a
phaser and then deactivates him. In the aftermath, Hugh becomes leader of the Borg group and the
Enterprise returns to Federation space. Data reports that Lore is to be disassembled permanently and that he intends to destroy the emotion chip, as it is "too dangerous", citing the harm he has inflicted under its influence. La Forge intervenes and advises him to keep the chip until he is ready. ==Production==