This could have easily been a DOCTOR WHO disaster on the scale of Christmas special "Voyage of the Damned" (which likewise featured a space-faring version of an iconic earthly transport), but thankfully "Mummy on the Orient Express" was a great deal better. A lot of that was down to Peter Capaldi's excellent performance, which balanced this Doctor's arrogance and unkindness with more of the boundless enthusiasm and eccentricity we've enjoyed from previous incarnations. I also liked the bravery of having the entire third act take place in a single train carriage... so it was a shame the horror element was a bit slapdash and the explanations stretched credulity.
One thing that worked nicely about "Mummy on the Orient Express" was the manner in which the titular boogieman was killing its victims; materialising after a tell-tale disruption of lighting, to stalk its intended victim for exactly 66 seconds before killing them with a touch to the head. The way an old-fashioned countdown clock would appear on the screen, literally ticking down to the fateful moment, delivered a lot of entertainment by virtue of its real-time ingredient. The mummy, eventually identified as mythical creature The Foretold (Jamie Hill), was also nicely presented in the Universal horror style, while also being invisible to onlookers, although it perhaps wasn't as terrifying as I think was intended.
The hour gave Capaldi a lot of wonderful, enthusiastic moments, but neglected a lot of the other characters—who just sort of stood around, in awe of him, which didn't fit with the idea these were some of the galaxy's smartest people. A dimwit engineer (played by comedian Frank Skinner, a keen Whovian) actually had more input into the creature's mystery than the assembled intelligentsia. Skinner, incidentally, was fine, but he's clearly no great actor and I think the role needed someone with more on-screen personality.
Overall, I enjoyed "Mummy on the Orient Express" for its stylishly opulent look, a great performance from Capaldi, some delightful nods to the show's past, and enough character work to make it seem plausible Clara has given The Doctor another chance after the events of "Kill the Moon". Although I think it's a shame the idea of their relationship breaking down wasn't pursued further, but unfortunately Doctor Who has weekly plot demands that get in the way of character exploration sometimes.
It's just a shame the explanations for almost everything in this episode were utter tosh, or simply not explained.
- It seems very likely this episode was inspired by a throwaway line in series 5's "The Big Bang", when The Doctor, Amy, and Rory left to deal with "an Egyptian goddess loose on the Orient Express, in space". We never saw that adventure, but one assumes it happened.
- David Bamber was a notable guest-star in this episode as Captain Quell; an actor with a strong link to showrunner Steven Moffat because he was the lead in his ill-fated '90s sitcom Chalk.
- The voice of GUS was provided by actor-comedian John Sessions. Grammy-winning pop star Foxes also cameod as the Orient Express's resident singer. The aforementioned Frank Skinner has apparently been angling for a guest-star role for years, until Steven Moffat finally relented and helped get him cast here.
- Did you catch the brief callback to series 1's "The Empty Child" when The Doctor asked The Foretold "are you my mummy?"
- It seems The Doctor once again likes jelly babies, which were a favourite of Tom Baker's incarnation. I also wondered if Clara's dismissal of a sarcophagus's contents as "just bubble-wrap" was an in-joke, because the green alien in Baker's "The Ark in Space" was famously created using bubble-wrap (when that material was cutting-edge and not so commonplace).