Guy Crayford was a British astronaut who piloted the experimental XK-5 space freighter, launched from Devesham, on its test run to Jupiter. The ship was lost, believed to have collided with an asteroid, and Crayford was presumed dead.
In fact, the ship was hijacked by the Kraals and Crayford was captured. He was brought to their home planet, Oseidon, and was brainwashed into thinking that his ship had crashed and his body had been severely damaged. The Kraals told him that they had rescued him and recovered all his body parts except for his left eye. They scanned his memories, found images of Devesham, and used them to construct a replica of the village and Space Defence Station, which they used to test their androids in preparation for their invasion of Earth. Crayford, convinced that Earth had abandoned him, aided them in their plans until the Fourth Doctor convinced him to remove his eyepatch, revealing that his missing eye was still intact and proving that the Kraals had lied to him. He turned against them, but he was shot and killed by Styggron. (TV: The Android Invasion)