April, her brother-in-law Oliver, and their families reunite in Cape Cod on an exquisite stretch of beach called Dawnland. After eleven summers of building traditions--kayaking, whale watching, bonfires, and ocean swims--this year comes with new threats both on and off the coastline.

Before their marriages, April and Oliver had an intense but disastrous fling that they kept hidden. Although they moved on with their lives, their more recent fiery encounter is getting harder to keep secret--especially as the week unravels, revealing fault lines not only between husbands and wives but between brothers, fathers and sons, and children growing up amid discord and lies. Ground zero for conflict is April's volatile teenage son, Lochlann.

The family structure begins to teeter. Secrets are surfacing. As everyone faces the consequences of their choices, the truth could finally forge them together or tear them apart forever.