Poirot and a Monster Problem

Oricle Poirot, the famous detective is summoned to the aid of Princess Elizabeth who has received a threatening note in the form of a paper airplane. She must meet the writer of the note at midnight.
Poirot pits his wits against evil baron von Frankenstune and his henchmen.
This short story is like no other Poirot story. Here, we have comedy galore with innuendos and double entendres.