In exclusive Star Island, Miami, blood isn't always thicker than water . . .

The night of his fiftieth birthday, software billionaire Jack Warren went missing hundreds of miles out to sea, his blood spattered aboard his yacht. His mistress, Ava Day, was charged with his murder—but she had already vanished without a trace.

Ten years later, detective Lila Day refuses to believe that her beloved sister, still in hiding after all these years, is a killer. To clear Ava's name and solve this long-cold case, Lila asks her friend Teddy Hawkins to do what he has done before: send her back in time, to solve the crime before it takes place.

And so she goes back to 2008, with only a month to prove her sister's innocence and bring Warren's real killer to justice. Lila fakes her way onto his city-like yacht and learns everything there is to know about his inner circle and glamorous hangers-on—even his family and the crew are her suspects. But as she dives deeper into the world of corporate intrigue, and the night of Warren's birthday draws closer, the truth becomes murkier than ever. And then Lila makes a terrible discovery, one that changes everything she thought she knew about her sister—and herself.