Episode P1.14
Alan seems increasingly addicted to time travel plots. Such delightful impossible nonsense! Killing Hitler et al! And he has not even had to deploy Section 31 yet! (TW cannot wait to strap himself into tight leather trousers.)
As a light break he has gone back in time to get Van Gogh to paint a heroic portrait of him standing proudly in front of the Saucer. But the resultant picture makes him wonder whether he has, all along, been meddling with powers he can't possibly comprehend.