A fifty-year-old cold case involving California royalty comes back to life—with potentially fatal consequences—in this gripping standalone novel from the New York Times bestselling author of the Mary Russell and Sherlock Holmes series. A magnificent house, vast formal gardens, a golden family that shaped California, and a colorful past filled with now-famous artists: the Gardener Estate was a twentieth-century Eden. And now, just as the Estate is preparing to move into a new future, restoration work on some of its art digs up a grim relic of the home's past: a human skull, hidden away for decades. Inspector Raquel Laing has her work cut out for her. Fifty years ago, the Estate's young heir, Rob Gardener, turned his palatial home into a counterculture commune of peace, love, and equality. But that was also a time when serial killers preyed on innocents—monsters like The Highwayman, whose case has just surged back into the public eye. Could the skull belong to one of his victims? To Raquel—a woman who knows all about colorful pasts—the bones clearly seem linked to The Highwayman. But as she dives into the Estate's archives to look for signs of his presence, what she unearths begins to take on a dark reality all of its own. Everything she finds keeps bringing her back to Rob Gardener himself. While he might be a gray-haired recluse now, back then he was a troubled young Vietnam vet whose girlfriend vanished after a midsummer festival at the Estate. But a lot of people seem to have disappeared from the Gardener Estate that summer when the commune mysteriously fell apart: a young woman, her child, and Rob's brother, Fort. The pressure is on, and Raquel needs to solve this case—before The Highwayman slips away, or another Gardener vanishes.