Mr. Waverly comes to Hercule Poirot's office to ask for his help on a serious matter: he has been receiving anonymous letters warning him not only that his son, Johnnie, will be kidnapped, but even specifying the exact time! Poirot and Hastings go to Waverly's mansion, and soon Inspector Japp and his men follow them. But will all these precautions be enough to stop this audacious crime?
Agatha Christie wrote a grabber of a premise here, but one that also kind of leads the writer into a difficult spot: after all, if the child is in the company of several people at the critical time that the letters specify, how can he possibly be kidnapped? Only if one of those people does something that allows the kidnapping to happen, and as soon as you spot that person and his "mistake", you know who's behind it all, at least in part. As Poirot says to Hastings at the end, "it was obvious". Perhaps the main point of interest in this very early Poirot episode is to see how fully the 4 main actors (Suchet, Fraser, Jackson and Moran) have already adjusted to their roles. (**1/2)