“Don’t judge a book by its cover.” That axiom has been drilled into us from an early age and, yet, picking up Peter Nichols’ new book The Rocks, it’s hard not to be seduced by the cover image: the turquoise waters of the Mediterranean, the island of Majorca, a sunny glow, gorgeous cliffside residences… All signals are pointing to a good beach and/or vacation read, something to entertain and transport you as you idle in the sand, right?

The Rocks is and it isn’t. If you’re looking for a light, fluffy read — keep moving. Nichols’ novel pulses with a dark undercurrent — not always comfortable, at times disturbing — but is thrilling and wonderfully written nonetheless; you can’t put it down. The plot centers on an elderly ex-couple, Gerald and Lulu, who were briefly married 60 years ago. They live in the same small Majorca town — he’s a former sailor-turned-writer; she runs the resort Villa Los Roques (The Rocks) — but, still harboring the same feelings of hatred and bitterness, have barely seen each other in all those decades since the split. Until they bump into each other at a market on page two. By page seven, they’re dead; fighting with one another, they’ve fallen and tumbled off a ledge into the sea.

The book works backwards from that point — from 2005 back to 1948 — uncovering the circumstances of their relationship and the reason for their intense animosity. Nichols keeps the mystery taut — their secrets aren’t unraveled till the end — and throws in a second romantic complication, involving Lulu’s son and Gerald’s daughter. It’s a multi-layered story — all the dramatic touchstones of intrigue, glamour, emotion are there, plus drug smuggling in Morocco, expat life, scenic Mediterranean vistas, parties and a certain undeveloped roll of film…