The 2293 escape of Kirk and McCoy from the Klingon penal asteroid Rura Penthe, arranged as a trap by their captors and turned into a rescue by the Enterprise-A.
The escape takes place in Star Trek VI: The Undiscovered Country. Convicted of the murder of Chancellor Gorkon, Kirk and McCoy are sent for life to the dilithium mines of Rura Penthe, a frozen world where a magnetic shield prevents beaming. A fellow prisoner, Martia, offers to guide them out.
Martia is a shapeshifter. She leads them across the ice beyond the shield, and Kirk realises that the escape has been set up so that they can be reported killed while fleeing. She takes his form and the two fight until the commandant arrives and shoots her.
Spock has tracked a viridium patch he placed on Kirk's shoulder, and the Enterprise-A, slipping through Klingon space, beams the pair up just as the commandant is about to name those behind the plot.