A warning is being spread through a Cyber-Fleet, a warning that the Doctor has infiltrated them. On one of the ships, the Seventh Doctor is setting up a Nemesis mine, as he has done on the other ships. With the push of a button, he'll be able to destroy the entire fleet. Suddenly, a Cyberman enters the room, proclaiming it has found the Doctor. However, the Cyberman just stands there, doing nothing. When the Doctor asks why it hasn't eradicated him yet, the Cyberman calls him, "Professor," revealing that the Cyberman is a converted Ace.