Like I said last week, I'm a bigger fan of the Doctor's trips into the future -- and/or to other worlds -- than I am of the past, so "Gridlock" had plenty to make me happy: hovercraft traffic jams, interspecies dating/breeding(*), a dead government on autopilot, and of course the final(?) appearance of The Face of Boe.
((*) Though I'm not clear: are the kittens Mr. & Mrs. Brannigan's babies or their pets? Do the cat-people begin life as kittens? Does that only happen with human/cat-people hybrids? Or are they just plain cats? Valerie calls them "children" a few times.)
Russell T. Davies' script does a wonderful job of painting the motorway as a kind of dystopian hell: a never-ending traffic jam the authorities and the upperclass have completely forgotten. Instead, it's revealed to be the salvation of the blue-collar citizens of New Earth, spared the drug-induced genocide of the rich people up above, then kept alive in a kind of benign neglect through the life force of our man Boe. You think it's the worst thing that could have happened to them, you assume the TV presenter's "We're so sorry" sign-off is an apology for keeping these poor people trapped down there, only to realize just how lucky the motorists and citizens of the undercities really are. (Given that the world above was killed "in seven minutes flat," I assume the Face of Boe produced that recording somehow.)
It really amazes me how often the show's able to play that same kind of "Everybody lives!" note from "The Doctor Dances" in season one and still affect me. When the Doctor gets the roof open and Valerie gathers the kittens and tells them, "Children; that's the sunlight," I definitely got a lump in the ol' throat, even though the show's gone to this particular well a half dozen times or more over two-plus seasons. I think it just goes to show how great Davies is at establishing a world and an epic scale so quickly; when the Doctor's around, miracles don't feel routine, even though he so often performs them.
"Gridlock" is also interesting as the first episode where the Doctor acknowledges the way he's been treating Martha as a place-holder and nothing more, as well as the first time Martha realizes how dangerous life with the Doctor can be.
It's also the first moment of David Tennant's tenure when he gets really upset over the destruction of the Time Lords and Gallifrey; until now, Ten has been largely defined as the guy who let go of all the baggage Nine was carrying, but as he talks about Gallifrey, you realize that while the face has changed, the heart's the same, and that hurt still aches over all that it's lost.
(Or is it all lost? Before it dies, the Face suggests the Doctor isn't alone; I don't know what's coming, but I wouldn't be surprised if there's another Time Lord floating around out there. After all, how do you wipe out a race of time-travelers? Wouldn't at least one or two of them still be hanging out at Versailles or the Jersey shore or the end of time at the moment when Nine ended the Time War?)
Finally, I would be remiss in discussing the episode if I didn't point your way towards Ross Ruediger's review over at The House Next Door -- specifically, his paragraph where he discusses the origins of the Macra (the giant lobster thingees that menaced Martha) in an old black-and-white Patrick Troughton episode. Here's a sample:
When the Macra showed up in “Gridlock”, every single old school Who fan popped a boner (yes, even the ladies). Why we did this, I do not know. We did not ask for Macra, we did not care much about Macra, but we were puzzlingly, orgasmically elated to finally see some fuckin’ Macra.Seriously, go read it. I'll wait.
What did everybody else think?