In Agatha Christie’s famous mystery novel, Murder on the Orient Express, a surprising but supremely unsatisfying conclusion arrives when genteel Belgian detective Hercule Poirot figures out that the gruesome murder was actually committed simultaneously by every single one of the suspects he’s been circling around. I read as much of Christie’s work as I could absorb when I was younger, but it was this book in particular that left me with the most disquieting feeling.…