The end we start from

"As London is submerged below flood waters, a woman gives birth to her first child, Z. Days later, she and her baby are forced to leave their home in search of safety. They head north through a newly dangerous country seeking refuge from place to place. The story traces fear and wonder, as the baby grows, thriving and content against all odds ... a lyrical vision of the strangeness and beauty of new motherhood, and a portentous tale of endurance in the face of ungovernable change"--Page 4 of cover.