Sam Doyle was one of the crew of the Guernica. He was born in 1909.
In 1959, he and Henry Goddard were chosen to pilot the Guernica to investigate the Mariana Trench. When they reached the bottom, an alien parasite got into the submarine and infected Sam, making Henry trap him outside. The parasite fed on Sam's memories for fifty years until they ran out. In 2009 it used Sam to call for help, then attacked the Octopus Rock when Torchwood Three came to investigate. The parasite abandoned Sam when they tried to escape and went after the Torchwood team. (AUDIO: Submission)