On a searing summer Friday, Eddie Chapman has been stuck for hours in a traffic jam. There are accidents along the highway, but ambulances and police are conspicuously absent. When he decides to abandon his car and run home, he sees that the trees along the edge of a stream have been burnt, and the water in the stream-bed is gone. Something is very wrong. When he arrives home, the power is out, and there is no running water. The pipes everywhere, it seems, have gone dry. Eddie and his wife, Laura, find themselves thrust together with their neighbours while a sense of unease thickens in the stifling night air.

Thirst takes place in the immediate aftermath of a mysterious disaster - the Chapmans and their neighbours suffer the effects of the heat, their thirst and the terrifying realisation that no one is coming to help. As violence rips through the community, Eddie and Laura are forced to recall secrets from their past and question their present humanity.