The Nemesis is of a silver color and is capable of speech. It can change its appearance and told Ace that she had past forms that would have scared Ace.
The Nemesis is powerful and can cause great destruction. Its last form was of the Lady Peinforte holding a bow and arrow. In order to use her power, all three pieces were needed: the statue, the bow, and the arrow.
If the statue were at all destroyed, it can reform.
The validium first arrived on Earth in Winsor in 1638 and was found by the evil Lady Peinforte who made the Nemesis into a statue of her holding a bow and arrow. She planned to use it for evil but the Doctor, knowing of its power, secured the statue onto a Rocket Sled and fired it into space.
However, the Nemesis entered an orbit that brought it back to Earth every 25 years and with it came destruction. It landed in the following years and cause the following events...
- 1913: eve of the First World War
- 1938: Hitler annexed Austria.
- 1963: John F. Kennedy was assassinated.
Now, the Nemesis returned to Earth in 1988. It was followed by the Lady Peinforte, who traveled through time to reach 1988; De Flores, a neo-nazi who wished to begin the fourth and final reich; and the Cybermen, lead by the Cyber Leader, who planned to destroy Earth with the combined forces of the Nemesis and the fleet of Cyber-Warship.
With all three pieces of the Nemesis and De Flores dead, the Doctor handed the Nemesis to the Cyber Leader. Gone mad, Lady Peinforte ran to the Nemesis and merged with it, although she was still alive. The Cyber Leader commanded the Nemesis to rendezvous with the Cyber-Fleet. The Rocket Sled launched and upon enter the fleet, the Nemesis exploded, destroing the thousands of Cyber-Warships as well as Lady Peinforte.