Plot summary
The Enterprise brings aboard the Betazoid Federation emissary Tam Elbrun (Harry Groener), and takes him to a distant star system. Elbrun, whom Deanna Troi (Marina Sirtis) previously knew when he was a mental patient, has a history of mental instability due to his overpoweringly strong telepathic capabilities, but his unique skills are used for first contact situations with alien life. However, some of the crew, including William Riker, mistrust him, due to an incident during another first contact situation in which he was involved with another Federation ship. A misunderstanding broke out that led to the deaths of 47 Starfleet personnel, including two of Riker's friends from his Starfleet Academy class and the ship's captain.
On this particular mission, Elbrun's abilities are needed to try to coax a giant sentient spaceship, codenamed "Tin Man", away from a star that is about to go supernova. It also comes to light that the star is in a Romulan -claimed area of space, and that this is a race to claim the ship. Elbrun finds it impossible to filter out the thoughts of the Enterprise crew. Elbrun finds solace in developing a friendship with Lt. Commander Data (Brent Spiner), by whom Elbrun is initially puzzled, finding what he calls "absence of mind"; Data, being an artificial lifeform, has no organic mind to be read.
When they arrive, the Enterprise is attacked and disabled by a Romulan Warbird that has overly stressed its engines to catch up to them. The Romulans race ahead to try to communicate with Tin Man. When Elbrun gleans from the Romulans telepathically that they intend to destroy Tin Man if they cannot claim it, he sends a telepathic warning to Tin Man. Tin Man suddenly comes to life and emits an energy wave that destroys the Warbird and further damages the Enterprise. Elbrun, now in communication with Tin Man, reveals that it calls itself Gomtuu.
The creature is millennia old and formerly had a crew, but they were lost in a radiation accident. Due to a combination of remorse, loneliness, and a lack of purpose, Gomtuu wishes to die in the supernova. Elbrun requests to be beamed aboard the creature, but Captain Jean-Luc Picard (Patrick Stewart) is cautious of this action. When a second Warbird arrives, Picard lets Elbrun transport to Gomtuu along with Data to help procure the ship. Elbrun is initially overwhelmed by Gomtuu, but eventually comes to identify himself with the ship.
With the supernova imminent, the elated Elbrun informs Data he will stay with Gomtuu, believing it is where he truly belongs. Moments before the start of the supernova, Gomtuu creates another energy wave that sends the Enterprise and the Warbird spinning out of the star system in separate directions before they are caught in the nova blast. As the Enterprise regains control, they find Data aboard the bridge; he reports what happened aboard Gomtuu. When Data discusses the events with Troi, Data comes to realize that like Elbrun with Gomtuu, the Enterprise is where he belongs.
Credits
Adapted from Wikipedia contributors, Tin Man (Star Trek: The Next Generation). Paragraphs and formatting adjusted; illustrations, reference markers, block quotations and non-story material omitted.