Hugh was found in the Argolis Cluster at the crash site of a Borg scout. Hugh himself was critically injured. He was brought back to the Enterprise for medical attention by Dr. Beverly Crusher at the protest of Captain Picard. Upon arriving on the Enterprise, Hugh was thrown in the brig and kept under guard at all times. He had trouble adapting to his new environment, having been cut off from the resources of the Collective for the first time in his life. Where there had been millions of voices in his head, there were now none. Dr. Crusher eventually nursed him back to heath, and chief engineer Geordi La Forge found a way to nourish the drone similar to the regeneration alcoves among a Borg ship.
Captain Picard saw this as an oppurtunity to destroy the Borg once and for all. He ordered La Forge and Lieutenant Commander Data to devise a method to destroy the collective through an implanted program or file in Hugh, much like Data had done to a Borg Cube through Captain Picard (as Locutus) two years earlier. Dr. Crusher did not agree with this course of action, they were talking about exterminating an entire race--even if it was the Borg.
As Hugh spent more time with the Enterprise crew, he learned many things. Geordi taught Hugh that humans did not want to be assimilated into the Collective, which contradicted what Hugh had been taught by the Collective. Geordi gave Hugh his name, through a mispronunciation of the word "you" (ironic given that Hugh himself was unable to comprehend singular pronouns at the time, he always refered to himself as "we"), and became Hugh's first ever friend. Guinan, who originally wanted nothing to do with Hugh, taught him that resistance is not futile. Gunian's homeworld had been destroyed long ago by the Borg, but the fact that Guinan was still alive was proof that resistance is not futile.
Picard eventually confronted Hugh. Hugh immediately recognized Picard as Locutus, and Picard took the role of Locutus while talking to Hugh, to simulate the authority that Hugh was used to. However, Geordi, Guinan, Data, Beverly, and other members of the Enterprise crew had a profound effect on Hugh. When Picard reminded Hugh that resistance is futile, Hugh said that resistance was not futile. When Picard told Hugh that Geordi will be assimilated, Hugh stated that Geordi did not want to be assimilated. When Picard said that this was irrelevant, Hugh specifically said that he (and Hugh used the word I, his first use of a singular pronoun) would not assist in the assimilation of Geordi. Picard was stunned that a Borg drone would say such things.
Picard decided that he could not send Hugh back with the file that would destroy the Borg. He offered Hugh asylum on board the Enterprise, but Hugh said that the collective would not stop looking for him until they found him. Hugh agreed to go back to the crash site, and to be taken back into the Collective, to protect the Enterprise from harm. (TNG: I, Borg)
After the Enterprise
Hugh's newfound sense of individuality proved to be almost as deadly to the Collective as any file stored in Hugh's memory could be. His experiences on board the Enterprise were spread to other drones, and eventually Hugh's cube had fallen into a complete state of disarray. The Borg's sense of shared identity had been disrupted, and they were no longer able to function. The cube was found drifting in space in 2370 by Lore, Data's brother. Lore took advantage of the confused drones and assumed leadership of the group of Borg. He brought order to chaos, and allowed the drones to maintain their individuality but was able to control them.
Hugh disapproved of Lore's leadership, and while Lore had acquired a ship and had built a base on a remote planet, Hugh took a group of drones underground and became a leader himself. Hugh and the drones loyal to him assisted the Enterprise crew in rescuing Picard, Geordi, and Troi and recapturing Data from Lore. (TNG: Descent, Parts I and II)