As Colin McGrath and his seven-year-old daughter embark for Hare Island in autumn, he is given grave warning. Don't go after the leaves drop, says the old groundskeeper. A moist wind picks up but Colin will not be swayed off course. The island is where he and his wife Alice met as children. She was the bright but crippled daughter of a wealthy Boston couple. Colin was the illegitimate son of her housekeeper. They formed an unlikely bond and swore an oath under shallow-rooted trees and distant constellations. Every summer, the two returned like the stars—until Alice left for the island alone in September and disappeared. Colin tries to leave Homicide police and news reporters behind on mainland Massachusetts. Hare Island could offer enough distance to forgive his own unfaithful heart and accept death, but Colin’s daughter Alma won't listen. She asks why her mother left her wedding ring behind. She asks who keeps calling Colin's phone and why he has given up the search. Alma decides to find her missing mother before a renegade piece of the polar vortex reaches the Atlantic Coast. There is a haunted cabin where no one dares look, not even the groundskeeper. She disappears into the white frenzy of a snowsquall ready to join Alice and the rest of the island's ghosts. OATH STONE is both a suspense and family saga. The major narrative thread layers Colin and Alice's past and present on Hare Island like onionskin. The minor thread follows a private investigation into the likely homicide of Alice, who was a respected estate lawyer and champion poker player. Retracing her last steps leads to Foxwoods Casino, a dangerous underworld, one of New England's richest families and then one of its most desperate.