Daedalus

Dr Emory Erickson, the inventor of the transporter, joins Enterprise with his daughter Danica to test a long-range sub-quantum transporter in a desolate region called the Barrens. Fifteen years earlier, his son Quinn vanished during an early transporter experiment. Soon a strange anomaly appears aboard ship, and crewman Burrows is killed by delta radiation. Archer discovers that Erickson has lied to him, and T'Pol identifies the anomaly as a kind of photonic ghost. Erickson admits the truth: it is Quinn, still conscious and trapped in subspace, and the real purpose of the test was to bring him home. Despite the deception and Burrows's death, Archer allows one final attempt. Quinn is rematerialised, but his body suffers severe cellular degeneration and he dies moments later, allowing his father at last to let him go.