Ah, Captain Jack Harkness. The loveable rogue of the Doctor Who universe. Not seen on screens since the end of Torchwood: Miracle Day, and not seen in Who since the end of David Tennant's reign, the Captain is long overdue a reappearance. Indeed, there will be some viewers who've never actually watched him in action, which is a travesty. We don't appear to be any closer to a return, but there was at least a glimmer of hope in The Woman Who Lived, with him being mentioned by the Doctor in a conversation with Ashildr, and the line: "He'll get to you eventually." Hopefully he'll get to us first.