The Fateful Bargain by Betty Neels
Dutch surgeon Sebastian van Tecqx had offered Emily's father the chance of a life-changing operation. But favours don't come cheap, and he expected something in return. It wasn't hard for Emily to exchange her drab nurse's lodgings for Sebastian's luxurious home, but how could Emily stop herself from falling in love with her charismatic employer? Especially once Sebastian made it clear that marriage was not part of the bargain.