Boston PI Sunny Randall is back to investigate the disappearance of a hard-partying energy drink mogul, in the latest thriller in Robert B. Parker's bestselling series.

After a near-death experience, Sunny Randall is ready to lighten her load as a PI, that is until she is called upon by billionaire media magnate Bill Welch to investigate the disappearance of his son, Dylan, the cofounder of the Gonzo Energy Drink company. Lazy, unscrupulous and a notorious partier, Dylan isn't exactly reliable. But Dylan's mother, Lydia, insists this time is different. She knows him. He's her son. And she believes he's in serious danger.

Unable to turn down the Welches' life-changing offer, Sunny takes on the case, starting off by befriending Dylans smart young business partner, Sky, who seems like his polar opposite. Sky is bright, innovative, ambitious and empathetic　yet surprisingly, she adores Dylan, and desperately wants Sunny to find him.

As Sunny traces the marks left behind by Dylan's past, she must unearth all the skeletons in his closet. She discovers not only his bad behavior with women, but also his reckless moves within the business world, producing an energy drink that, despite its marketing, has proven dangerous and even deadly. Still, Sky insists he's a good man. Who is Dylan, really? And why has he vanished? When bodies start to pile up, Sunny must find answers quick, before she—and those she cares about—get caught in the crossfire.