Mathematician (Silver Nemesis)
From Tardis Wiki, the free Doctor Who reference
This mathematician worked for Lady Peinforte, working out the date of Nemesis' return to Earth. In 1638, he eventually dated it to 23 November 1988. In order to travel there, Peinforte prepared a concoction, the last ingredient of which was human blood. She killed the mathematician to get this. (DW: Silver Nemesis)