The Year of the Flood is in the same setting as Atwood’s Oryx and Crake with many of the same characters featured. As a prequel to Oryx it is a good stand-alone novel, although there is a slight focus on the characters who become Oryx and Crake respectively.
The plot centres around a ‘Waterless Flood’ which takes the form of a deadly pandemic. This has been foreseen and prepared for by a minor eccentric environmental psudo-Christian movement, who style themselves after Noah preparing for the biblical flood. We hear from different perspectives what life was like in the build up to the pandemic and those who survived looking for and defending themselves from other survivors.
Atwood creates believable and terrifying distopian futures well, and this is no exception.