After a massive anxiety attack, Sam Atkins left his high-powered job in the City and committed himself to life on the road in a small van. Six months in, he's running out of savings and coming to the conclusion that he might have to go home to his emotionally abusive family.

Needing time to think, he takes a walk through a copse by the Cornish roadside, only to stumble upon the body of a ritualistically killed sheep. As he's trying to work out what the symbols around the animal mean, the sheep's owner, Jennifer, and her nephew, Ruan Gwynn, come upon...