Zachary Cross Flane

Zachary "Zack" Cross Flane was second-in-command of the Walker Expedition in the 42nd century.

Biography
Captain Walker was killed when their ship crashed on the planet Krop Tor after encountering K37 Gem 5, the black hole the planet orbited. Zachary took command. Although reluctant and unsure of himself, he dealt successfully with the attack by the Beast. He evacuated the survivors in a spaceship. He bestowed posthumous honours on his fallen crew, including the possessed Toby Zed and the Ood they had been forced to destroy. After the Tenth Doctor and Rose saved him, he returned to Earth. He represented the Torchwood Archive on the expedition. (DW: The Impossible Planet, The Satan Pit)