Archie Sylvest

Professor Archie Sylvest (PROSE: The Twin Dilemma) was the father of Romulus and Remus Sylvest. He was worried that his sons' mathematical genius could be used to alter reality on a massive scale. When he discovered that they had been abducted, he alerted the Interplanetary Pursuit Squadron, who sent Hugo Lang to find them. (TV: The Twin Dilemma)

Behind the scenes
Sylvest's first name was not included in the original TV story, but rather given in the novelisation.