5 things The Doctor's soon-to-be-revealed biggest secret could be

The Doctor's Name

The literal translation -- Doctor Who? equates with the Doc's given name. How could that be a big reveal? Well, maybe it'll turn out that he is a person from history who we already know. Or maybe this is a huge fakeout and his name is Ralph. Ralph the Time Lord. There have been weirder reveals in the shows 50-year history.

We keep hearing this question -- Doctor who? But what does that really mean?

With Doctor Who returning to our screens in less than a week and producers insisting that we'll never guess the Doctor's biggest secret and that, when we find out, our jaws will drop, we decided it's time to look over the possibilities.

So what does "Doctor who?" mean, and what might be his big secret? Chances are it'll probably be a mixture of a few of these, but let's lay them all out on the table.