One little bit survived. A tiny nugget of Nestene Consciousness lived on.

It had escaped the Doctor’s antiplastic by hurrying into the substrata and hiding inside the nearest available shape: the body of a clown.

Days before, the Nestene had posted sentries along the embankment in the form of living statues: those strange humans, who decide to earn a living by dressing up as clowns, robots, or statues, and then standing perfectly still, waiting for people to throw money at them. What an odd, odd species.

But now the plastic guards had dissolved, except for one. A white-faced Pierrot, well, half a face - half a head, its right half. A crescent of head perched atop a rough neck and glittering silver bodysuit with one eye, bright as insanity, and a bisected leering grin.

The half-head Pierrot hauled itself up onto the opposite bank of the river, and looked back at the grave of the Consciousness. The secret underground layer had collapsed, causing the whole of the London Eye to tilt forward and collapse into the Thames.