Plot summary
The Enterprise discovers a crashed escape pod in an unexplored star system. The crew find one critically injured passenger and bring him aboard the ship. Dr. Crusher determines the survivor will live due to his amazing recuperative powers, and notes that his cells are mutating.
When the stranger awakens, he has no memory of his identity; Crusher nicknames him " John Doe ". As weeks pass, John recovers physically, but occasionally suffers from severe pain which is somehow tied to his ongoing mutation. He also begins emitting strange, bright energy bursts. John soon discovers that he can use this energy to heal injuries.
In the meantime, Geordi La Forge investigates a device recovered from John's vessel and determines the location of John's home planet. However, John's memory has begun to return, and he senses that he must not return yet. Soon, a vessel approaches the Enterprise, and John declares he must leave. He tries to steal a shuttlecraft, and accidentally knocks Lieutenant Worf from a walkway with an energy burst, killing him. John uses his healing powers to revive Worf. Prevented from escaping, John explains that he wanted to leave as he is becoming a danger to himself and the crew.
Commander Sunad of the intercepting ship communicates with the Enterprise, announcing he is from the planet Zalkon, and that John is a criminal facing a death sentence. Captain Picard refuses to release John to the Zalkonians without more information as to the charges. When Picard mentions John's strange powers, Sunad is alarmed and triggers a device which causes the entire Enterprise crew to become unable to breathe. John heals everyone aboard the Enterprise with one bright flash of his energy.
His memory now restored, John teleports Sunad to the Enterprise and explains that his race has reached a new stage in evolution, in which they are becoming beings of energy. His homeworld's government fears what is happening and kills any who show the signs of change; John and others were escaping from their homeworld when attacked. John then becomes the first to complete the transformation, becoming invulnerable.
John offers to help Sunad make this transformation as well, but Sunad still refuses. John sends Sunad back to his own ship, warning him that their government can no longer keep their people in ignorance. The Zalkonian ship retreats. John bids the Enterprise crew good-bye, transforms into energy and departs the ship.
Credits
Adapted from Wikipedia contributors, Transfigurations. Paragraphs and formatting adjusted; illustrations, reference markers, block quotations and non-story material omitted.