Featuring the Doctor and Amy, as played by Matt Smith and Karen Gillan.
This story takes place sometime after 'Vincent and the Doctor', but before 'The Pandorica Opens'.
She dreams of things she can't quite remember, a face she can't quite make out; days in the park, on the village green. She remembers games and stolen kisses and jealousy and his hand in hers, and she remembers a warm weight on her finger, a dress hanging on her wardrobe.
She remembers him, until she wakes up. He bleeds away from her the way dreams always do. He disappears and she forgets him, because she has to; because remembering would hurt too much.
Amy Pond wakes up in the middle of the night, wearing an oversized t-shirt from Musée d'Orsay's little shop and underwear, and the TARDIS seems quiet. She wonders if they've landed, because the engines seem muted, but it's more than that. The intrinsic light of the TARDIS, the glow that seems to emanate from the skin of the time ship itself, is dimmer than it normally is.
Her footsteps echo as she pads down the hall, and she finds the control room empty, the time rotor still. The monitor is dark, and there's no sign of the Doctor.
She checks the sickbay, and the library, his drawing room, the two galleries that she knows of, the swimming pool, the galley. He's nowhere to be found. She goes into the bowels of the ship, where the dust is thick, where it floats in the dark, chill air heavy and mostly undisturbed. She walks past doors much like her own, and she imagines there are other bedrooms behind them, and she wonders which of his old companions lived there.
He doesn't tell her about them, but he does sometimes, when she annoys him enough, when he's melancholic enough. After their visit to the Trojan gardens, he told her about Vicki, and about Katarina; he told her about Romana when she asked about the Time Lords, and he told her about Donna, his hearts breaking before her eyes, when she asked why he seemed to be avoiding London these days.
After what feels like an eternity of searching, she hears his voice. She's about to call to him, but something stays her. A door is hanging slightly ajar, light streaming from it.
Inside, she sees the Doctor. He's standing in what looks almost like a cathedral; a spire, reaching up and up and up, tiny alcoves built into the wall, rising in tiers from where the floor, where the Doctor stands, looking up. There's movement in the alcoves, and Amy realises that they're holograms.
Dozens of them, all moving; all people, smiling, laughing. She recognises some, from when she tricked the TARDIS into showing visual records of its previous inhabitants.
The Doctor taps at the controls on a lectern in front of him, and one of the alcoves lights up. A man appears before the Doctor, a hologrammic representation of an odd-looking guy, with short, spiky hair and a big nose. He seems to be speaking, but there's no noise. It's just a visual record, and nothing more. His voice is gone.
Without realising it, Amy's crying.
She pushes open the door, and steps inside. "Who is he, Doctor?"
The Doctor spins around to her, slapping the controls. The entire room goes dark, the holograms dropping offline one by one, the man before the Doctor disappearing first.
Tears streaming down his cheeks, Amy demands to be told.
"He's someone I lost," the Doctor explains, and he apologises. "They're all people I've lost. My old friends."
Amy swallows, scared and angry and sad for a reason she can't figure out. "What is this place?"
The dark cathedral looms around them, and the Doctor steps towards her. "It's a memorial, Amy. It's how I remember them." He doesn't add that he won't ever forget.
"Who was that man?"
The Doctor frowns. "Do you remember him?"
Amy tries to speak, but she can't. Does she remember him? Has she seen that face before? Amy shakes her head, wipes away her tears and says "No. I don't."
The Doctor sighs, and touches Amy on the forehead. He escorts her back to bed, and looks back inside the room as she falls asleep, and knows that when she wakes up in the morning, she'll forget it all; but he knows that he'll remember Rory Williams, like he remembers all of them.