Erik Hass

 was Miranda Pelham's assistant. By the time they went to Ashkellia, they had been working together for twelve years and been lovers for three. When he partly opened the Tomb of Valdemar, he was driven mad and physically transformed. He attacked the bathyscape she and the Fourth Doctor and Romana were in. When it was exposed to the planet's poisonous atmosphere, Erik was killed. (PROSE: Tomb of Valdemar)