Seven hours in the past. Seven days in the present. Seven survivors remaining. Who will you save?

A decade ago, two vans full of high school students on a school service trip crashed into a Tennessee ravine—a tragedy that claimed the lives of several classmates and teachers. The nine students who managed to escape the river that night were irrevocably changed. A year later, after one survivor committed suicide on the anniversary of the accident, the rest made a pact: to gather every year to commemorate that horrific night.

To keep each other safe.
And to hold each other accountable.
Or both.

Their annual reunion spot, a house on the Outer Banks, had always been a haven. But by the tenth anniversary, Cassidy Bent had worked to distance herself from the tragedy and the other survivors. She'd changed her cell phone number. She'd blocked others' email addresses. This year, she was determined to cut ties for good. But on the day of the reunion, she received a text message with an obituary: another survivor had passed away. Now they were seven, Cassidy found herself turning to the group, overwhelmed with grief and doubt.

Almost immediately, something seems off this year. Cassidy is the first to notice that Amaya, the annual organizer, is missing, looking exhausted. This wouldn't have worried them if it weren't for the impending storm. Suddenly, they're facing road closures and rising waters... again. Then Amaya stops answering her phone. After everything they've been through, she wouldn't intentionally make them worry. Would she?