At the end of season 6, Doctor Who fans were teased with a rather obvious, but very elusive, question.

In "The Weeding of River Song," Dorium told the Doctor that the Silence believed that ""On the fields of Trenzalore, at the fall of the eleventh, when no living creature can speak falsely or fail to answer, a question will be asked, a question that must never, ever be answered."

According to the blue fellow's severed head, that question is "Doctor who?"

While the topic has been avoided throughout season 7, today the BBC released the poster and title for the final episode of the season. Aptly titled "The Name of the Doctor," the season finale may reveal an answer.

"There's going to be a revelation," show runner and episode writer Steven Moffat told the Radio Times. "I'm not teasing. I'm not wrong-footing you - you're about to learn something about the Doctor that you never knew before. And I think you're in for a shock."

The poster feaures the Doctor standing behind the broken panes of a window, possibly that of the Tardis.

While the BBC tells viewers to "stand by for something that you might always have believed to be impossible," what fans do know for sure is that River Song, played by Alex Kingston, will be returning for the first time this season. The episode will also introduce a new monster, the "Whispermen."