The Wrong Way Down

An amateur sleuth with an eye for fakes is on the lookout for a murderer in this mystery by Agatha Christie’s favorite American author.
What begins as a courtesy call on his wife’s friend, Miss Julia Paxton, turns into another case for Henry Gamadge, antiquarian book dealer, handwriting expert, and amateur detective. Miss Paxton presents Gamadge with a mystery: a framed etching that had always hung in the hallway of the Ashbury mansion has suddenly sprung an inscription dated 1793. Miss Paxton swears nothing had been written on that portrait before the previous Sunday. Did Iris Vance, a relative and professional medium, made it happen? And how? Henry Gamadge is pretty sure the solution to this mystery has nothing to do with the supernatural, but he can’t quite make out what it all means. Was it a joke? Petty larceny? Or is something much more dangerous going on, and has Gamadge somehow stumbled onto a criminal conspiracy?