One, Two, Buckle My Shoe by Agatha Christie

A routine visit to the dentist turns into a baffling case when the dentist is later found dead. As Poirot investigates, what appears to be a simple crime quickly expands into a complex web involving political intrigue, blackmail, and hidden connections among seemingly unrelated individuals. With multiple layers of deception, Poirot must carefully reconstruct events to uncover a truth that reaches far beyond the obvious.