Why DID the Doctor leave Gallifrey all those years ago?

As we enter the home stretch of this year’s Doctor Who, among the many questions on fans’ lips are who or what is the prophesised hybrid warrior, and what was the Doctor’s part in creating it?

We’ll probably have to wait until the series nine finale to find out for sure, but one fan (who previously made a goodbye tribute for Jenna Coleman) has decided to whet our appetite by creating a surprisingly slick trailer for the storyline, which goes back to the Doctor’s earliest days.

Cutting together scenes from Davros’ speech about the hybrid from this series, clips of First Doctor William Hartnell and many other stories (including a brief shot from non-fiction drama An Adventure in Space and Time) the trailer lays out the mysterious storyline in full, and even suggests a few candidates for who the hybrid warrior could be.

After all, there have been a lot of hybrids in Doctor Who, whether it’s Maisie Williams’ Ashildr or Ingrid Oliver’s Osgood from this series or Human/Time Lord metacrisis Donna Noble, who’s presumably still out there somewhere. But which one is it?

All we know is, if the actual storyline turns out to be as exciting as this trailer we’ll be a perfect mix of happy and excited. In other words…