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