It was a dark shape, something like a black bundle on a pole.
'Here, let me look!' said Hal. He plunged through the light and reached out to grasp the pole. But his hand went straight through it. 'Did you see that?'

But none of the others were taking any notice. Instead they were gazing in horror at the sight in front of them. It was a head, stuck on top of what must have been a sharpened stake. Blood dripped from its severed neck. As they watched, the head began to revolve slowly to face them.