First appeared 1966

Arriving in London 1966, the Doctor feels an evil force pulling him towards the Post Office Tower. It is WOTAN – a super-computer so clever that, unbeknownst to its creator Professor Brett, it has developed an intelligence of its own. Taking over those around it using hypnosis, WOTAN begins construction of a fleet of War Machines to subjugate the world. The First Doctor was able to capture a War Machine, reprogamme it and send it back to the Tower to destroy WOTAN.