Ted Matlock worked for an agency with ties to the European government. He and his associate Alison Hayes were placed on the Hotel Galaxian to prevent a weapons deal between Dorothy and Neville Adler and the Selachians.
He sent a distress signal for help, which was picked up by the Second Doctor. When the Adlers discovered his identity, they used their AI weapon to kill him. The Doctor and Hayes hypothesised that Matlock had contacted the Doctor using a frequency the Doctor would later leave behind on Earth for such eventualities. (PROSE: The Murder Game)