The Outer Limits (1995) (1995)

S1E13 Quality of Mercy

Major John Skokes finds himself captured by an enemy during a brutal interstellar conflict against a seemingly invincible alien species. The stakes rise when he realizes that his fellow prisoner, a young cadet named Pri, is undergoing a terrifying transformation into one of their captors. Skokes must devise a plan to escape, not only to rescue Pri but also to prevent a shocking truth about the war from coming to light.