It’s Amy’s wedding day; she should be happy, she’s marrying Rory, and she loves him with all her heart. Her parents are here, which is wonderful and slightly hard to believe, though she doesn’t know why. Everything is perfect, and yet she’s sad, perhaps sadder than she’s ever been in her life.
It’s as if something is missing, something she can’t identify but which she knows should be here because she feels its absence. So she’s drifting in limbo through what should be the happiest day of her life, waiting for some kind of sign to tell her what’s wrong.