There’s nothing like a good Doctor Who cliffhanger. Russell T Davies knows this well, having given us such edge-of-your-seat, “oh-my-god-I’ve-got-to-wait-a-week-to-find-out” extravaganzas as the Doctor talking down the Daleks in Bad Wolf; the Genesis Ark reveal in Army of Ghosts; Yana revealed as the Master in Utopia; and the Bad Wolf sequence in Turn Left (unfortunately this reviewer was on holiday when The Stolen Earth aired, so was oblivious to David Tennant‘s would-be regeneration for two whole weeks). It’s disappointing that one of Doctor Who‘s shortest seasons to date hasn’t had a two-parter, or even a cracking cliffhanger, until this penultimate instalment, but it’s certainly one for the ages.

For those who haven’t seen The Legend of Ruby Sunday yet – here be spoilers…

The opening of the episode is straight to business with a TARDIS arrival sequence that feels right out of a blockbuster film, spinning towards the new U.N.I.T H.Q. With forty-five minutes of pulse-pounding set-up to get through, there’s no time to waste. Davies’ script juggles a huge plethora of characters from this new era of the show in a way that we haven’t seen since his last stint as showrunner. Seeing Yasmin Finney back as Rose is nice, although her role feels a lot smaller than it perhaps should do (and the reference to a bi-generated Fourteenth Doctor is kept vague and brief), while Jemma Redgrave‘s Kate Stewart can’t seem to get through a single episode without an explicit mention of her late father, the Brigadier (a Who regular between 1968 and 1989, who later appeared in The Sarah Jane Adventures). The flashes of Susan Twist playing a blue alien and a cyborg were a little odd (perhaps the upcoming Fifteenth Doctor novels will expand on this), but there’s no denying that “Susan is the name of my granddaughter” is a cracking cliffhanger in and of itself leading into the opening title sequence.

Inevitably, with The Legend of Ruby Sunday being the first episode in a two-part story, there’s a lot being thrown out there without much in the way of explanation. The Time Window sequence is brilliantly put together (it was great to see the behind the scenes footage on Unleashed afterwards), and incredibly suspenseful to watch on a first viewing, yet we still end up with more questions than we do answers. That being said, I did particularly enjoy the Doctor taking the mickey out of U.N.I.T’s technology (after The Church on Ruby Road, it’s clear that this Doctor has strong opinions on time travel). It’s not made clear exactly what S Triad Technology is, who Susan Triad is and what it all has to do with our main villain’s plan. Despite working undercover there, Bonnie Langford‘s Mel doesn’t seem to have found out very much, other than that tech billionaire Susan Triad (played by the aptly-named Susan Twist) is surprisingly nice – which means there’s definitely something going on.

Director Jamie Donoughue injects the proceedings with some dynamic camerawork, maintaining such a fast pace that it becomes easy to overlook how much of this instalment is just getting everything in place for the actual revelations in next week’s concluding episode. Having said that, it does raise the bar considerably for the season finale to resolve a lot of seemingly disparate threads. Anita Dobson‘s Mrs Flood seems to be aware of what’s going on for instance, although I wouldn’t be too surprised if her fourth-wall-breaking storyline isn’t wrapped up in next week’s episode.

Everything is building to that cliffhanger reveal though. The sandstorm glimpsed in the trailer. Susan Triad Technology. The Pantheon of Gods. And there’s even a Harbinger for them. When the eerie vocal talents of the great Gabriel Woolf started reverberating around our heroes, there could only be one villain (even if Murray Gold‘s theme for the Master was playing at the time, in a confusing musical choice). Sutekh, the legendary one-hit-wonder villain from the acclaimed four-part serial Pyramids of Mars, has returned. Where he treads he brings nothing but dust and darkness. After forty-five minutes of the characters discussing theories that the audience at home have had (“Is Susan the Susan? Isn’t S Triad an anagram of TARDIS?”), the Osiron God himself has returned through the time vortex, claimed the Doctor’s TARDIS and now endangers the entire universe.

Will The Legend of Ruby Sunday hold up on subsequent viewings? It’s far too early to say. Suffice it to say that this is the closest to the edge of my seat I’ve been watching Doctor Who for a long time, and after that cliffhanger, I’m very much looking forward to the Empire of Death…

(And before that, a bonus episode of Tales of the TARDIS – almost as exciting!)

Doctor Who continues on BBC One next Saturday at 18:40

Join us for our series blog review next week