A mythical sapphire, a family legend, and a lost treasure, could lead Carly Harden to her fondest dreams . . . or her worst nightmare. Now that Carly has revealed her secret, that she knows who and what Team Nightly is, Tony Sargento, chef of the Blue Mermaid restaurant, empath, and Carly's boss, is furious with her. His jealousy at Carly's close friendship with Rhett James, the newest team member, isn't helping him calm his anger. That she's been in love with Tony since the day they'd met, is one thing she would never disclose. His anger at her is breaking her heart and her past is preventing her from trusting him fully. In order to help the team locate an artifact that Gordon Charles, King of the Vampires, is after, Carly digs a little deeper into the family lore behind the key that she's worn on a chain since she was a little girl. She soon comes to believe that it is one of three needed to open a lost treasure chest. One that is said to hold the Mermaid's Heart: a massive sapphire that is said to hold mystical powers and created by Zeus himself. The powers that legend has attached to the Mermaid's Heart, are said to be boundless, granting the one who holds it their fondest wishes. But when Gordon Charles gets word that Carly is the owner of one of the fabled keys to the Heart, he sends his minions to retrieve it, no matter the cost. After Carly is attacked and nearly killed, Tony and Rhett must try to set aside their ongoing battle, to win her heart, in order to protect her. Even with the help of Team Nightly, it may not be enough to save her . . . unless they find the Keys to the Mermaid's Heart.