After being injured and facing loss in the line of duty, retired Boston Police Detective Jeff Jackson returns to a quiet life of fishing, living in his late father's home on Martha's Vineyard. When a mysterious visitor to the island turns up dead, Jeff is reluctantly recruited to help in the investigation by the local police chief, a family friend. Adding a layer of complication, Zee Madieras – the chief's daughter and Jeff's former flame – is the medical examiner on the case. As the murder investigation casts suspicion on some of the town's most powerful and wealthy citizens and brings Jeff and Zee's lives in peril, they race to solve the case before another murder strikes the peaceful vacation town.