There are a lot of books that concern the Hearts.
http://sylviahubbard.com/2007/12/21/heart-novels/
I think that’s the update version of the list.
there’s also a category on this blog with the heart of Detroit in it
http://sylviahubbard.blogspot.com/search/label/Hearts%20of%20Detroit
Now to know the whole story, because in each book there are bits and pieces of the story here and there, but the one book that may say it all would be Sex Weed.
(I’m still in love with this cover)
You even get a glimpse into the famous King Heart so if you’ve never read it, get it, if you’ve read it, read it again.