Not long after Isabel "Izzy" Chambers opens up a knitting shop in the sleepy fishing town of Sea Harbor, Massachusetts, a diverse group of women begins congregating each week to form the Seaside Knitters.
Izzy raises some eyebrows when she rents the apartment above her shop to Angie Archer, whose reputation for loose behavior and a quick temper has made her unpopular with many locals. But could any of them have wanted her dead? Angie's body is discovered drowned in the harbor, her long red hair tangled like seaweed in a lobster trap.
An official investigation rules the death an accident. There are speculations of too many whiskey sours, a slippery wharf, a dark night... But Izzy and the Seaside Knitters smell something fishy. When several strange incidents occur above the shop, the women decide to take matters into their own hands. But before long, their small-town sense of security is frayed, and the threat of more violence hangs over this tightly knit community.