His Wicked Games — Ember Casey

Trapped with a billionaire in his mysterious mansion... Can she beat him at his own game? Lily Frazer would do anything to save the Frazer Center for the Arts -- even take on the infamous billionaire Calder Cunningham. When Lily breaks onto the Cunningham estate, she only wants to find and reason with Calder. (All right, all right, she wants to punch him in the face, too, but that's Plan B.) As it turns out, the arrogant billionaire is willing to give her the money he promised, but there's a catch: she must win it from him. And the games he has in mind aren't exactly... innocent. Lily isn't about to give up the money without a fight (or let some haughty bastard seduce her), but she quickly discovers that there might be more to the brooding Calder than she initially perceived. As their games of cat and mouse become increasingly intense, she suddenly finds herself confused by her own emotions. Can she deny her attraction long enough to win the money she needs?