Stormcage. River Song comes waltzing down the corridor, the skirt and bustle of her taffeta dress swaying like a bell to unheard music. Alarms sound. She picks up a nearby phone. "Oh, turn it off," she says, all smiles. "I'm breaking in not out!" Then, just in case there were any doubt as to her identity, she adds: "This is River Song, back in her cell." Why do these people even bother trying to lock her up? She informs the poor schmoe on the other end that she'd like her breakfast at the usual time and then continues her waltz down the hall.
Within a few steps, she sees the silhouette of a man wearing a cape. "Oh, are you boys dressing up as Romans now?" she asks archly. "I thought nobody read my memos." Considering the revelation at the end of the episode, it's a good thing the flirtation ends there. Rory steps out of the shadows and introduces himself, not sure if they've met yet in this time stream. She pales. Yes, they've met. She walks up to him, looks a bit starstruck, and breathes, "Hello, Rory." He stares back at her, puzzled. After a bit, he asks her what's wrong. She tells him it's her birthday. She says the Doctor took her ice-skating on the Thames in 1814, (If any time-travelers are considering taking me somewhere special for my birthday, please make it a time and place I don't have to wear a corset. Thanks.) She giddily tells him that the Doctor got Stevie Wonder to sing for her under London Bridge, unbeknownst to Stevie. You know, the guy's blind, not dumb. Pretty sure he would've noticed something was up.
Rory tells her he's come from the Doctor, too. River says it's a Doctor from a different time. Rory: "Unless there are two of them." River, suggestively: "Now, that's a whole different birthday." Later, after he's learned the truth and when everything is quiet and he is trying to sleep, Rory will think back on this conversation and the notion of River having a threesome with two Doctors will come all unbidden into his thoughts. And he will likely never sleep again. She consults her blue TARDIS journal as she heads to her cell. Rory tells her that the Doctor needs her, but she already knows about Demon's Run. Rory's puzzled, but she reminds him she's from the Doctor's future. Also, she's just awesome. She suddenly remembers this guy's dressed up like a Roman and asks him about it. Shouldn't she already know? Maybe her Doctor didn't mention sartorial details. Rory explains it was the Doctor's idea. The Doctor likes playing dress-up with him. River cites one of the Doctor's rules of engagement: "Float like a butterfly, sting like a bee." Pretty sure that was Muhammad Ali's rule, unless he got it from the Doctor. It doesn't even really make sense in this context, does it? Look like a bee, sting like a damned bee, too. She tries to keep joking around with him but he blurts out that Amy and their baby have been taken. River looks immeasurably sad, but also completely unsurprised. Rory tells her the Doctor's getting people together to rescue Amy and needs her help too. She declines the invitation, even though it obviously pains her. Rory is dumbfounded. She explains: "This is the battle of Demon's Run - the Doctor's darkest hour. He'll rise higher than ever before and fall so much further." History is painful enough when it's a memory, but knowing it's yet to come must be unbearable. "I can't be with him till the very end," she says. Rory is still confused. As she steps back into her cell, she says, "This is the day he finds out who I am."