The brains behind Doctor Who have delighted fans with fun series-specific easter eggs and references to pop culture for decades, and in 2015, that's no different. With the anniversary of Back to the Future, along with the release of [Star Wars: Episode VII — The Force Awakens](tag:711158), the clever writers decided to create an easter egg within an easter egg, and the results are awesome.
An imgur user posted this photo right after the episode, and right there in the background is graffiti in the style of Star Wars' Aurebesh writing -- but it's what the writing says that makes this the kicker.
Spelled out in Aurebesh is the word "DeLorean," which most folks know as the vehicle used by Marty and Doc to time-travel in Back to the Future.
That's one double-wammy of geeky goodness.