ULTIMA
ULTIMA was a machine designed by Dr. Judson and used by the British Army to decipher encoded German messages during World War II. At the time, it was the most advanced computing machine in the world. In 1943, a Soviet party, led by Captain Sorin, were sent to steal ULTIMA from the base at Maiden's Point. The Seventh Doctor and Ace arrived at the same time.
Dr. Judson and Commander Millington also used it to translate Viking runes which had been part of Fenric's game to set himself free. In 1943, ULTIMA reacted to a translation and shot green electricity at Judson, killing him. Fenric then possessed his body. (TV: The Curse of Fenric)
In the early 1970s, the journalist James Stevens began collecting reports of a series of agent provocateurs known as "the Doctor" who had been involved in unusual incidents. The ULTIMA Incident was the earliest such event that Stevens was able to uncover. However, it was still heavily classified by that time. (PROSE: Who Killed Kennedy)
