The moment where the Doctor and River silently and simultaneously realize company's coming, it is pretty beautiful. Around the planet, suddenly, there are "at least" ten thousand starships, River reports: Maybe bajillions, because her tech can only count so high. (Again, credit where it's due: This is the only time I can think of where the entirety of bad guys and aliens we've ever seen on the show could be in one place without feeling like Uncle Rusty had gotten ahead of himself again. I love, love this story.) There are: Daleks, Cyberships, Sontarans (yay!), Terileptil, Slitheen, Chelonian, Nestene, Drahvin, Sycorax, Haemogoth, Zygon, Atraxi, Draconian.
(Of interest particularly: The Nestene Consciousness, which I remembered as a pile of barf that you swing over like Indiana Jones, having completely forgot the majority of that episode, in which there were Robot Mickeys and Robot Cars and Robot Dumpsters going chomp-chomp-chomp and eventually a silly mannequin hand which was like the one thing Eccleston ever did that wasn't entirely about making you cry until you passed out with your thumb in your mouth.)
After a moment of just naked, little-boy fear, the Doctor runs around with twice the crazy from a second ago, and his body language gets very flouncy and scared and very, very much in need of a hug. (Maybe a shower, maybe that would help.) The thing I guess starts opening? Some reason, the Doctor beats ass up to the surface, and the ladies follow, and up in the sky it's very beautiful and starshippy and rainbow lens-flares galore. River begs him to run, just like this one time, because check it out: "Everything that ever hated you is coming here tonight. You can't win this."
Of all the things you just don't say to the Doctor, I would put that at the top of the list.
The Doctor pulls out his binocs and stares up and decides that he's going to employ "the greatest military machine in the history of the universe." The Daleks? Amy asks. The Sontarans? I obsessively ask, as always, with the Clerics from the Byzantium of course as my second wish. But no, obviously he's talking about the Romans.
Who -- when our heroes arrive on horseback -- are just full of piss and vinegar. The Doctor and River are taken into custody (Amy stayed back at Stonehenge, where every single one of the Doctor's enemies over 900 years are hanging out) and the commander yells for awhile about how it's funny that "Cleopatra" has been chilling with them all week, even though she's both in Egypt and dead at this point in history. There are various sci-fi noises and camera-shaking tectonic scares because of all the spaceship baddies, which has got the commander's skirts all in a tangle as well.