Rough Waves. The Shark's Double Secret, #1

Shark shifters and romance! First novel in a hot new trilogy.  When Tara accepts a free trip to the Caribbean, she's expecting azure ocean and powdery beaches. Instead, she gets trapped in a mansion with Spencer, the enigmatic biotech billionaire. The same man she had an ill-fated fling with. Soon, Tara stumbles onto Spencer's dark secrets. Spencer has been gambling with his life, trying to find a cure that will save shark shifters from a dangerous toxin in the ocean.
He needs time and luck, and to avoid all distractions. Instead, he gets Tara, the brilliant, stubborn woman he's been trying to forget. He wants her more than ever, but if he gives in, many innocent marine shifters will die. Desperate, Spencer proposes a deal that will keep Tara far away from his bed and his secrets. But it backfires, leading to an explosion neither could have predicted.