Picard sends an Away Team to investigate the wreckage of a small craft, where they find the only survivor is an adolescent Borg. The Captain initially shows no sign of wanting to help, however, Dr. Crusher eventually persuades to beam the creature aboard in spite of the fact that his presence on the ship could alert the rest of his race. Back on board the Enterprise, Beverly disconnects the command center that allows the Borg to communicate with the rest of his race. Troi senses anger in Picard, who was kidnapped by the Borg, but he refuses to discuss his feelings. However, those feelings become apparent when Beverly discovers that her new patient's brain implants have been damaged and asks Picard if Geordi can construct new ones. Picard realizes that if Geordi can tamper with the command structure of this Borg's brain, he can destroy the entire race through their interconnected network.
Beverly is shocked that Picard would use the creature she is trying to heal to kill. However, the rest of the crew agrees with the Captain, citing the race's history of warlike activity against the Federation. Later, the Borg wakes up confused and disoriented after being disconnected from the collective whole.
In the science lab, Geordi and a reluctant Beverly attempt to communicate with the Borg so that Geordi can learn more about the command pathways in his brain. As they talk, they find this Borg is harmless and innocent — unlike the other Borg they have met. They name him Hugh, and Geordi begins having second thoughts about programming the creature to destroy his race. When he tells this to Guinan, she reacts with fear and anger. Later, Picard and Riker discover that a Borg rescue vessel is headed their way.
Guinan visits Hugh and angrily tells him how the Borg destroyed her race, but the creature actually shows sympathy toward her plight. Later, Geordi tells Picard he is having second thoughts about using Hugh to destroy the Borg, but Picard will have none of it — until Guinan convinces him to talk with Hugh himself. Hugh immediately recognizes Picard as Locutus, the creature Picard became when the Borg kidnapped and tried to assimilate him. However, Picard is surprised to discover that unlike the rest of the Borg, Hugh is exhibiting human emotions.
Persuaded by his encounter with Hugh, Picard abandons his plan to destroy the Borg. Instead, he offers Hugh the choice of either returning to the crash site to be rescued or remaining on board the Enterprise permanently. Hugh is tempted by the offer to stay with his new friends, but opts to be returned to the crash site to ensure the safety of the Enterprise. He exchanges sad goodbyes with the crew before Geordi returns with him to the crash site. There, he tells Geordi he does not want to forget his experiences through re-assimilation. As Geordi watches the Borg rescue party reclaiming their lost brother, Hugh meets his eyes, offering hope that he will remember their friendship.