Emma is beginning to wonder whether relationships, like mortgages, should be conducted in five-year increments. She might laugh if Chris had bought a motorbike or started dyeing his hair. Instead he's buying off-label medicines and stockpiling food.

Chris finds Emma's relentless optimism exasperating. A tot of dread, a nip of horror, a shot of anger - he isn't asking much. If she would only join him in a measure of something.

The family's precarious eco-system is further disrupted by torrential rains, power cuts and the unexpected arrival of Chris's mother. Emma longs to lower a rope and winch Chris from the pit of his worries. But he doesn't want to be rescued or reassured - he wants to pull her in after him.

Darkly funny and beautifully written, When the Lights Go Out is a novel for our times: a story about cultivating hope and weathering change.