Surd

From Tardis Wiki, the free Doctor Who reference

Surd was the deaf mute manservant of Baron Maupertuis.

Maupertuis did extensive experimental surgery on Surd. He created insulated spaces in Surd's head and chest, which could be used to conceal items. Maupertuis smuggled the journals of Siger Holmes out of the Library of St John the Beheaded inside Surd.

The experiments also resulted in Surd gaining pyrokinetic abilities, which he used to kill people when the Baron ordered him to do so. He was killed by Lord John Roxton in India before he could murder John Watson and Bernice Summerfield. (PROSE: All-Consuming Fire)