The figure rising from the water is impossible. It’s looks like an astronaut, dressed in a suit that could have come from the Apollo moon landings. It doesn’t belong here, and yet it does. The Doctor has seen it before, knows what it’s there for, and knows what has to happen next.
This moment is a fixed point, it’s inevitable, and it can never be changed.
Or can it?
Trapped inside the suit, River is helpless, watching as her prison zaps the man she loves over and over, just as she saw once before.
Only this time, it isn’t him.