Based on the acclaimed novel, Jodie Comer, Joel Fry, Katherine Waterston, Mark Strong and Benedict Cumberbatch deliver tour-de-force performances in this intimate and poetic portrayal of family survival. When London is submerged by catastrophic floods, a new mother (Comer) is separated from her partner and embarks on a dangerous, remarkable journey across the country in search of safety, all while protecting her baby from the surrounding chaos.