Billionaire’s Proposal by Rachel Cook

He’s a billionaire in need of a fake wife.
She needs his money to save her sister’s life.
And he’s about to make a proposal she can’t refuse.

With her sister’s rare illness taking its toll, Harper knows she can’t hope to cover the mounting medical bills—or give her the life-saving experimental treatment she needs. But is accepting a reclusive billionaire’s money really the right answer?
The last thing Blackwell Stone wants is to get married, but to keep his life and business, he needs a wife. So when Blackwell meets a reporter in desperate need of money, he proposes a solution: a fake marriage for one year. What could go wrong?

Turns out, everything.
Harper’s sister will die without his money. Blackwell’s world will crumble without her. But can they survive a year together and come out the other side with their hearts—and souls—in one piece?