Bratanian Shroud

The Bratanian Shroud was a creature that lived within the electrical impulses of the mind. It originated from a dimension other than N-Space which had different physical laws. It could control the minds that it was feeding off of. (AUDIO: Repeat Offender)

History
In 2144, the Shroud came to Reykjavik through a dimensional rift and attracted the attention of the Fifth Doctor, who defeated the Shroud using knowledge from an encounter with the Shroud in an aborted timeline. (AUDIO: Repeat Offender)

Aborted timeline
In an aborted timeline, the Shroud came to Reykjavik and killed the Fifth Doctor during their encounter. The Shroud went inside the Doctor's mind and drained him of artron energy, stopping him from regenerating. The Shroud continued to survive in Reykjavik by living in its wireless data transfer system. Wanting more artron energy, the Shroud attracted the attention of the Doctor at an earlier point in his timeline. This Doctor was killed by the Shroud as well.

The Shroud then brought an even younger Doctor that was travelling with Vislor Turlough to Reykjavik. The Shroud lured them to the apartment of Kat Gunnarsdottir and Lara Jensen and tried to kill them by possessing Kat. The Doctor exorcised the Shroud from Kat's mind with an adapted mediascreen, but he was found by Lara and almost arrested by Jill Sveinsdóttir. While this happened, the Shroud possessed Turlough. When Turlough tried to kill the Doctor, the Doctor exorcised the Shroud from Turlough and had Jill shut down Reykjavik's data flow. Without the data flow and a mind to live in, the Shroud died. (AUDIO: Repeat Offender)