It’s been months since Cassidy Shaw has heard from her mother, Rosa, a world-renown scientist. When she does, it’s in the form of an urgent edict to retrieve a key. Arriving at Rosa’s apartment in Cincinnati, Cassidy encounters strangers. One man who seems determined to silence her. The other, could he be her savior? Luke Dixon enters the fray, believing his neighbor is being attacked. Never one to ignore someone in distress, he’s then shocked to realize he’s the one needing rescue. Bound together through violence, Cassidy and Luke must come to trust each other as they embark on a search, armed only with the key and Rosa’s cryptic directions. It’s a journey with unexpected answers and decades-old research. A search with more questions…and a lethal enemy who returns when least expected.