The Doll Who Ate His Mother by Ramsey Campbell

It was a freak accident. The man had suddenly stepped into the road, and the breaks had failed. Clare could only steer wildly, the car finally crashing into a tree and on to the curb. Now her brother Rob was dead, silent in the passenger seat, slumped against the door. He died of massive head injuries.

But there was something else, something that at first she couldn’t quite grasp, that seemed in explicable. His right arm was missing. Gone. Someone had taken it.

Buy it here.