The Marsh Madness(Book Collector Mysteries‪)‬

Jordan Bingham works hard to improve Vera Van Alst's collection of classic detective stories. So when Chadwick Kauffman-heir to the Kauffman fortune-offers a very good price on a fine collection of Ngaio Marsh first editions owned by his recently deceased stepfather, she is thrilled to meet with him at his fabled summer estate, Summerlea.
The next day, Jordan and Vera are shocked to read that Chadwick has died in a fall from the grand staircase at Summerlea. But when the picture in the paper is of a different man, it becomes clear that the ladies are victims of a scam. And they'll have to unmask the imposter fast, because someone is trying to frame them for murder…