Shift Agent

Shift Agents were entities without solid bodies. They were capable of transferring their energy into mechanical objects, allowing them to control them.

When a case full of dark matter came to Earth in 1885, a Shift Agent came to Earth to retrieve it. It possessed a steam train, as it was the fastest transport at the time, and sent it to dangerous speeds to reach Euston station faster. The Doctor did not know of this and stopped the train. When he learned the truth, he helped the Shift Agent reach Euston station where it safely diposed of the dark matter before it did any serious damage. (DWAM: Track Attack)