Sorenson

Sorenson was a Morestran scientist who led an expedition to Zeta Minor in search of a new energy source to save his civilisation. He found what he believed to be it when he discovered anti-matter on the planet, but all the members of Sorenson's team were killed by an Anti-matter Creature. Months later, after being rescued by Vishinsky's landing party, he brought his anti-matter samples aboard Salamar's ship. He refused to believe the Fourth Doctor's warnings concerning anti-matter, and when Salamar ordered the samples to be returned to the planet, he took one and hid it on the ship. However, the anti-matter infected him, causing him to transform into an anti-matter monster which killed Morelli, De Haan and Reig. At first he tried to control the transformations with a vaccine he created, but eventually succumbed completely. When Salamar tried to kill him, he was killed instead but not before causing the creation of more anti-matter monsters which began killing more crewmembers. Sorenson was cured when the Doctor returned the last anti-matter sample to the planet. He then suggested that Sorenson look into using the kinetic forces of planetary movement as an alternate energy source. (DW: Planet of Evil)