This has some aspects of the In Death series, Duncan Swift is wealthy, he won a lottery a few years ago and now spends his time really doing what he wants, a lot of that making him money. He really enjoys it when his money makes the lives of those around him better, without charity.
She's Phoebe MacNamara, a hostage negotiator who is battling a few issues. Being a lone parent, having an agoraphobic mother, being chained to her house due to a complicated will and having to fight some pretty sexist workmates.
They meet when she tries to talk down a ex-employee of Duncan's. Duncan is entranced and decides that he's going to get her into his life. She's not sure he wants to deal with all her issues.
Then to complicate things it looks like someone has it in for her, or maybe several somebodies. The story kept me guessing until the very end and I really enjoyed it.
I've seen some reviews where they didn't like the more mystery feel but I found it a good read, I actually regretted putting it down.