Tyler resisted Dortmun's plans to attack the Daleks, as they didn't have enough men. In spite of his reluctance, he led the attack on the Dalek flying saucer. He was one of the few survivors of the attack. After the failed attack, he decided that London was too dangerous for them to remain, and stated he would look for more survivors and head north.
Tyler met up again with David, Susan and the First Doctor. He saved Susan from an alligator in the sewers.