The Doctor isn't entirely sure what he'd been expecting. She isn't River, for as much as she might look like her, breathe like her, make his hearts ache like her. She isn't her.

His head drops a moment, he knows a gentle 'get out' when he sees one (even if he's not usually too good at listening to them). But it's then that he sees the corner of a faded photograph as it slips free and falls to the floor. He reaches down and picks it up. He recognises it, Grayle, the collector.

"What's this?" he asks, presses. He knows. But that's not the point.