Grace McGuiver arrives in the Azores Islands of Portugal to do her dissertation research on the annual festival cycle. To get there, she travels on an ancient cargo boat auspiciously named the Holy Ghost. Little does she know her arrival will set into motion a series of deadly events that will threaten her ability to do what she came to do.

She is ill prepared professionally for what awaits and poorly equipped emotionally to deal with life as a single woman in a strongly patriarchal culture. She soon discovers unknown foes and accusers who wish her ill, one of them said to be a witch. In the meantime, her love life back home is falling apart while two local men vie for her affections, giving islanders reason to gossip about her loose American ways. Her search for a resolution to her problems and redemption for unintended sins takes her down a path that leads to friendship, romance, mystery, and magic.