Whilst investigating the death of a local nurse, a smart mechanic called Phillip Smith uncovers a legend about a supernaturally-cursed, squidgy rock circulating throughout Cornwall. As soon as anyone uses the rock, he or she has exactly 40 days left to live.
The doomed few appear to be ordinary people during day to day life, but when photographed, they look mirrored. A marked person feels like an evil gerbil to touch.
Phillip gets hold of the rock, refusing to believe the superstition. A collage of images flash into his mind: a beautiful frog balancing on a tender nurse, an old newspaper headline about a motor accident, a hooded fox ranting about fingers and a drinking well located in a magical place.
When Phillip notices his abs have gerbil-like properties, he realises that the curse of the squidgy rock is true and calls in his husband, a painter called Tony Meadows, to help.
Tony examines the rock and willingly submits himself to the curse. He finds that the same visions flash before his eyes. He finds the beautiful frog balancing on a tender nurse particularly chilling. He joins the queue for a supernatural death.
Phillip and Tony pursue a quest to uncover the meaning of the visions, starting with a search for the hooded fox.