The BBC Media Centre have released the synopsis for the pen-ultimate episode of series 9, episode 11, written by Steven Moffat and directed by Rachel Talalay.

Trapped in a world unlike any other he has seen, the Doctor faces the greatest challenge of his many lives. One final test. And he must face it alone.

Pursued by the fearsome creature known only as the Veil, he must attempt the impossible. If he makes it through, Gallifrey is waiting…

The episode airs 28th November. Time to be confirmed.