Contemplating the eating disorder she is trying to cultivate, lumpen, horny, 15-year-old Harmony is reminded of a Möbius strip: what to do when you need, but can’t afford, both Senokot and KitKats? Similar flares of mordant wit, as well as more painful spasms, punctuate Amanda Coe’s third novel, whose unfolding secrets eventually bring us full circle, back to the stony beach where her story begins. It is here that a mute, amnesiac woman is discovered by Harmony’s aunt, but perhaps the greater mystery surrounds Harmony’s mother, who has retreated into the vacancy not of silent forgetfulness, but depression. Coe’s bleak coastal town is a fitting backdrop for a novel that, for all its dark laughs and plot twists, ultimately seems to resign its central characters to the unhappy loops of their lives.

• Everything You Do Is Wrong by Amanda Coe is published by Fleet (£14.99). To order a copy for £12.74 go to guardianbookshop.com or call 0330 333 6846. Free UK p&p over £10, online orders only. Phone orders min p&p of £1.99