The Lighthouse by P.D. James

In The Lighthouse, master storyteller P.D. James brings Commander Adam Dalgliesh to a remote, windswept island off the Cornish coast — a private sanctuary for the rich and powerful. When a famous novelist is found hanging from the railing of the island’s lighthouse, the peaceful retreat is shattered, and a murder investigation begins.
With its isolated setting, closed circle of suspects, and mounting tension, The Lighthouse is a classic whodunit wrapped in P.D. James’s signature psychological insight and elegant prose. As Dalgliesh uncovers long-buried secrets among the island’s elite residents, the case takes an unexpected and personal turn.
Mysterious, atmospheric, and layered with moral complexity, The Lighthouse is a chilling meditation on power, secrecy, and the human capacity for violence.