1316. On the wilds of Dartmoor stands the isolated Priory of St Mary, home to the Sisters of the Knights of St John. People journey from afar in search of healing at the holy well that lies beneath the chapel.

But the locals believe Dartmoor was theirs long before Christianity came to the land. and not all who visit seek miracles. When three strangers reach the moor, fear begins to stir as the well’s water run with blood.

What witchcraft have the young woman, the Knight of St John and the blind child brought with them?

The sisters will need to fight for everything they hold dear as the ghosts of the old world gather in their midst.