Still Treads the Shadow

Avi Samara, a scientist and Kirk's early love, joins the Enterprise to study gravitational anomalies in the Cressida system, where a black hole is swallowing everything nearby. The crew pick up a heartbeat and trace it to the long-missing USS Defiant. On board, in cryostasis, is an elderly James T. Kirk: a duplicate created when the Enterprise rescued its captain from interphasic space during the Tholian incident. Stranded ever since, he has grown old alone, giving his dead shipmates a burial in space one by one. His only companion is the Defiant's computer, which has become a conscious being called Tiberius and is fiercely protective of him. When a Klingon cruiser arrives to claim salvage, the Defiant cripples it and the warship vanishes into the black hole. Tiberius then demands the old Kirk's return and, in revenge for being abandoned, threatens to merge two black holes and destroy the sector. As Spock and Scotty build a Trojan horse program, the elder Kirk has McCoy sedate his younger self and beams across to the Defiant with Avi. The Enterprise breaks free, the old captain seals the anomaly and sends Avi back, and the Defiant disappears with him. When Avi remarks that he is all alone out there, Kirk answers that he is not anymore.