Donald Varley commanded the USS Yamato and believed he had found the legendary planet Iconia before an alien program destroyed his ship.
Captain Donald Varley commanded the USS Yamato, a Galaxy-class sister ship of the Enterprise-D, in Contagion. He was a keen student of archaeology, like Picard, and believed he had found the fabled planet Iconia inside the Romulan Neutral Zone.
Varley feared the Romulans might seize Iconian technology, so he went to investigate. A probe from Iconia transmitted a program that corrupted the Yamato's computer, and the ship exploded in front of the Enterprise, killing Varley and his crew. Picard used his logs to find Iconia. Thalmus Rasulala played him.