Neil Gaiman has already established himself as one of Doctor Who's most celebrated writers and that's pretty impressive when you consider the fact he's only penned two episodes to date. They were both absolute corkers, though. The first, The Doctor's Wife, introduced fans to the Doctor's beloved TARDIS in physical form (and will no doubt go down as one of the show's most popular episodes ever as a result) while his second and most recent contribution, Nightmare in Silver, marked the re-emergence of the Cybermen against the backdrop of what had once been the greatest theme park in the galaxy. Viewers who have been vying for his return, though, will unfortunately have to wait a little bit longer. The man himself has recently confirmed that he hasn't got the time to commit to another episode at the moment but his fans will be pleased to hear that he's absolutely determined to write for the Twelfth Doctor which means it's likely he'll be back to make it a Doctor Who hat-trick before Peter Capaldi's era is over. The announcement that he'd be contributing to Doctor Who was met with a rapturous response on both occasions so it's safe to say that fans will welcome him back with open arms when he manages to squeeze it into his diary. Hopefully it will be sooner rather than later.