Recently adapted into a feature film for Netflix, Osman’s novel about a quartet of crime-solving British septuagenarians is even more delightful on the page — written with mordant, laugh-out-loud wit reminiscent of Martin Amis. As its title suggests, the book contains its share of dead bodies, but the tone is light, the story charming and the retirement home setting as inviting as a luxury resort. If you like it, there are four sequels (so far); the latest, “The Impossible Fortune,” came out in September.