Vengeance of the Vardans
From Tardis Wiki, the free Doctor Who reference
Vengeance of the Vardans was a computer game that Ace wrote in 1976 as a clue for her past self and the Seventh Doctor, to warn them of the Vardan invasion of Earth. The Monk interfered with the timeline, however, so that she had never written it, and the game never existed. Knowledge of the original timeline still existed on a videotape owned by the Monk. (PROSE: No Future)
