Bart Faversham was the friend of Sebastian Marten.
In 1920, Bart was in Lord Farthingale's country retreat when Sebastian Marten and Paul Steiffers were killed. During his investigation of these deaths, Dr Merrivale Carr gathered the house guests into the library, where he believed that the murderer was Kitty Kickshaw, who had taken the identity of Glenda Neil. Immediately after, the Ninth Doctor and Rose arrived, explaining the deaths were the result of "invisible aliens".
A haze appeared, accompanied by a buzzing sound. The aliens' spaceship had been releasing energy in an attempt to move out of being stuck between the time vortex and real space. The release of energy accidentally killed Bart by lifting him and throwing him into the fireplace. (PROSE: Doctor vs Doctor)