Billionaire’s Secret by Rachel Cook

He’s got dark secrets, and she’s determined to uncover them.
Their marriage was built on secrets and lies. They knew that going in, though. It was always meant to be a fake marriage…until things turned real…and they learned the secrets they had weren’t just the ones they shared.
Now Harper must uncover the truth, not just for the sake of her marriage—but to survive. Because some secrets have teeth.
And some secrets kill.
Billionaire Blackwell is a man with a dark past that’s coming back to haunt him and put everything he’s built, everything he’s fought for, in danger.
Including his wife.
As someone lurks in the wings to bring everything crashing down, can they overcome their obstacles and rebuild the broken trust? Or will their secrets destroy them both?