The Last Party by Cassidy Lucas

Good shape paperback book. For Los Angeleno Dani Sanders, turning 50 seems like one more disappointment. Her career has stalled, her nineteen-year-old daughter with developmental issues is regressing, and Dani’s ex-husband Craig, a fertility doctor worshipped by Hollywood’s elite, is forever upending her life. Though she doesn’t feel much like celebrating, she can’t say no when her best friend Mia Markle, a flamboyant and strong-willed actress, insists on planning a “creative” birthday weekend in the wild, wealthy bohemian enclave of Topanga Canyon. On the weekend of the Summer Solstice, Dani and her six closest friends gather in the hills above the canyon at “Celestial Ranch,” 18-acres of rugged, wooded mountainside where they’ll spend three glorious days hiking, practicing meditation and reiki, and enjoying lavish catered cuisine. They will also indulge in a little DMT, a short-acting psychedelic drug meant to open their senses and transport them to a higher plain. But as the weekend unfolds, long-buried tensions, unresolved grievances, and old secrets emerge, leaving Dani desperate for clarity about her life. Dani and her friends take the drug late at night on an open hillside beneath the glittering stars. When Dani returns from her intense and revelatory "trip," she learns that one of her friends has gone missing. Then another disappears. And soon, Dani finds herself alone on the dark mountainside, seemingly abandoned by the people who are supposed to love her most.