Many things about this were not good. The Doctor tried to dig his way to the edge of the puddle, but couldn't move his body for the undertoe. And, to his very unpleasant dismay, he felt something alive near his feet, slithering past his leg.

The Doctor reached out for Jack's arm, but he couldn't quite reach, his fingers, now slick with the alien quicksand, seemed to slip through.

"Try laying prone on the ground, and then reach for me, the angle should be enough to pull me out of the current," he said. The thing beneath the surface brushed his other leg. Or was it two things?

"And hurry!"