Doctor Who Series 8: 15 Obscure Easter Eggs You Probably Missed

14. Gus Already Tried To Get The Doctor On The Orient Express In A Previous Episode (Mummy On The Orient Express)

Mummy On The Orient Express was a typically fun Nu-Who episode, with a scarier-than-average monster, British comedian guest star and a sci-fi twist on an Earth-based thing. A third act rug-pull revealed that, far from being a innocent attraction with a supernatural nuisance, the whole train is a set up to get scientists to study the titular creature. The Doctor confesses to Clara that he's been invited to the space-train numerous times, even getting a call directly to the TARDIS. Clearly Gus has wanted to Doctor along for a long time. A really long time it seems - we saw that call way back at the end of Series 5 finale The Big Bang. It was implied that this was the first adventure the newly married Williams went on, but evidently something must have got in the way.