The Troxil Gamemasters were a race of shapeshifters who set off wars between "primitive species" and gambled on the outcome.

In the 1890s, the Gamemasters chose Earth as a target. With Europe deeply divided, the Troxils aimed to spark a war by assassinating Robert Gascoyne-Cecil, the Prime Minister of the United Kingdom.

A Troxil assassin tried to kill Gascoyne-Cecil once, but failed. On the assassin's second attempt, it was captured by the Paternoster Gang. Vastra fiddled with the assassin's teleport bracelet to send it back to the other Gamemasters with a message telling them to never try to interfere with Earth again. (PROSE: Assassin on the Railroads)

Community content is available under CC-BY-SA unless otherwise noted.