Exchange by Katherine Rhodes

Demons aren’t always evil, but sometimes, they have no choice…
Lincoln Foster plays by the rules.
He likes to beat the cheaters at their game by not playing along. There’s nothing more satisfying than to make a legal million.
Dr. Wren Warner is in a desperate position. She and Fischer need to find their adopted daughter’s brother–a young innocent boy they want to call their son. But, neither her nor Fischer or their friends have access to the wealthy classes who know where Ben is.
Lincoln does.
He agrees to play a dangerous game, breaking his own rules about not breaking the rules. The reality the Lincoln faces is like nothing he could ever have imagined.
Wren and Fischer are there for him, as much as they can be. Wren doesn’t want to like Lincoln, as arrogant and greedy as he is, but she can’t deny there’s something about him– and Fischer is strangely calm about this man who clearly has designs on his woman.
All of them are uncovering truths that scare them. Truths that are bigger than they could have possibly imagined. Truths that, once uncovered, could change the very fabric of their world.