A Blue Moon is a rare occurrence, a time when strange things happen, when the vast universe might reveal its darkest mysteries, or at least that's what Jack Graves has always heard. Jack is a teacher in the quaint New England town of Wickham, a place where nothing changes and life moves lazily along. But Jack's serene world is about to be torn apart. A teacher with summer's off and time on his hands, Jack should be at his leisure, tending to his house and yard, and helping his wife, Joanna, a librarian, sell her wares at the annual Summer Harvest Fayre. But things on Jack's quiet dead end street are not what they appear. Someone is stalking the couple, creeping about their yard after dark and leaving grisly 'deposits'. But Jack, not wanting to alarm his wife, enlists the aid of his eccentric friend, chemist 'Gospel' Tom Williams, a man whose investigatory skills are as good as 'Gospel', who sets about analyzing the evidence. But when Jack's neighbor is brutally murdered and 'Gospel' Tom's findings suggest that something amazing has been happening on Jack's once peaceful street, the Graves' household and the entire town of Wickham are plunged into a dark realm where myth and reality merge and even those closest to Jack may not be who or what they seem to be.