Doctor Who: Red Twilight

In the distant future, the Doctor has lived countless lifetimes; gone on an infinite number of adventures. In all of them, the universe has never ceased to be beautiful, even in its darkest hours. There has never been a time when life in some form hasn’t been worth living. …Except once.Now, determined for the universe to never find out what happened, the Doctor is running. From his secrets; from a creature that’s never going to stop chasing his companion, and from an old enemy who shouldn’t exist. He can’t stop. He can never stop. But even in a Time Machine… some things can’t be outrun.