Deep Water follows three different women as they face the repercussions of some very difficult choices. The women, who all know each other from the school gate with children around the same age, include Lisa, a mum-of-three who runs a business and is married to a taxi driver, Roz, a debt-riddled physiotherapist who finds a dangerous way out of her situation and Kate, a wealthy and organised mum who seems to have it all together.