After years of learning how to manage her bipolar disorder, Emily Firestone finally has it under control. Even better, her life is coming together: she's got a great job, her own place, and a boyfriend, Paolo, who adores her. So when Paolo suggests a weekend sailing trip, Emily agrees--wine, water, and the man she loves? What could be better? But when Emily wakes the morning after they set sail, the boat is still adrift...and Paolo is gone.

A strong swimmer, there's no way Paolo drowned, but Emily is at a loss for any other explanation. Where else could he have gone? And why? As the hours and days pass by, each moment marking Paolo's disappearance, Emily's hard-won stability begins to slip.

But when Emily uncovers evidence suggesting Paolo was murdered, the investigation throws her mania into overdrive, even as she becomes a person of interest in her own personal tragedy. To clear her name, Emily must find the truth--but can she hold onto her own sanity in the process?