The Heiresses is a perfect cottage read — especially if you happen to summer on Martha’s Vineyard, like the family at the heart of this Gossip-Girl-meets-the-Kennedys whodunit. The Saybrook family heads a diamond empire and enjoys every luxury. They’ve also suffered a series of tragedies, leading the gossip sites to deem them cursed. When Poppy, the current company president and picture-perfect mother and wife, is found dead, an anonymous website runs the sinister headline: “One Heiress Down, Four to Go.” From there, Poppy’s four female cousins — the heiresses — start to come undone. They all have juicy secrets that could make them suspects — or the next target. Toss in a slew of men behaving badly, and you’ve got a thoroughly enjoyable book for adults — no surprise coming from author Sara Shepard, the YA master behind the Pretty Little Liars series.