‘Someone tried to move the Earth once before, a long time ago…’ The closest Doctor Who has come to one of the Marvel Avengers movies, as the ‘Children of Time’ assemble. At the time, this was true event television – possibly the last time my whole family watched TV together. Even my mum, permanently sniffy about the series, was drawn in. Years later, it’s easy to pick flaws with this. The TARDIS zipping about gives an illusion of movement that’s not really present in the script, which unfolds as a series of scenes on the guest stars’ stock sets: Sarah Jane in her attic, Torchwood in the Hub. Martha at least gets to teleport from New York to her mother’s front room, but this is a way from the vertical chases of Army of Ghosts, or the thriller elements of The Sound of Drums.

This is full of RTD tics that, to some, were becoming tiresome: another Earth invasion (the Daleks in the streets scenes are very evocative of the Cybermen sequences in Doomsday), another story that’s about the absence of the Doctor – coming straight after Turn Left. Hand-waving pseudo-SF like the teleport base code or the subwave network. The scene of Martha reacting to the Earth’s theft replays the similar scene in Smith and Jones – motif, or just running out of ideas?

However, I think all these have to be taken in context: this is the last time the series is going to try anything like this: it’s a distillation of the current approach, a Planet of the Spiders end of an era piece (even including a regeneration), and a celebration of everything that’s been achieved since the show came back. It would have been weirder not to have tried something like it.

What we get is the modern equivalent of The Five Doctors. There’s a huge cast to incorporate – so huge, that the guest stars overspill the opening credits. All the modern companions are here, getting a Terrance Dicksian hallmark moment (Martha returns to her family at the end of the world; Jack makes a pass at Sarah Jane; Sarah Jane gets to be brave and defiant; Rose gets to bash down the doors of the universe to get at the Doctor; Gwen gets to reassure Rhys; Harriet Jones does her ID thing). Things that have been mentioned in the past suddenly appear, like Rassilon in The Five Doctors – the Shadow Proclamation and the Medusa Cascade. Old baddies get a mention or a moment – the Judoon, the Sontarans, the Slitheen, the Adipose, the Pyroviles (what a shame they couldn’t afford to have a crowd of angry aliens in the foyer of the Shadow Proclamation).

There’s also a sense of RTD taking the opportunity to get a few things off his chest. Sarah Jane deplores Mr Smith’s fanfare. In a couple of scenes, Torchwood is functioning better than in most Torchwood episodes. The shoe is on the other sock as Rose is jealous of Martha. The cliffhanger, the most creative use of regeneration since Destiny of the Daleks, is a masterpiece. Every episode 12 invariably gets something monumental (‘Rose, I’m coming to get you’; the Daleks emerging from the Sphere; Martha returning to a fallen Earth), but this goes beyond all of them, playing a clever game with an audience constantly primed for Tennant’s departure. 2008 was full of these teases between The Stolen Earth and The Next Doctor. The internet buzzed with theories. It was perhaps the most exciting time ever to have been a Doctor Who fan. Watched outside of that context, you might just think this was good. In context, it’s probably the greatest Doctor Who episode ever.

Next Time: Journey’s End