The cheerful atmosphere at the county fair is marred when the judge of the baking contest dies of poisning, and from a cake that his own wife baked.

The maid, also one who entered the contest, goes to Mr Keen. The suspected woman has fled, and the maid wants her found. The maid is jealous of the young bride, and shares secrets of the household with Mr Keen. Might it be a case of the maid doing the poisoning, and letting the wife take the fall? Mr Keen sets out to figure it out.

All the points of the law are against the wife, and there’s nothing on the maid other than circumstantial evidence. The first step is to find the wife, and get her side of the story. As she explains things, Mr Keen has a plan to trap the killer.

With all the key players gathered together, the killer cracks, and shows their hand. .

As is typical, Mr Keen tells the true story of the crime in the end. Listen, and find out how it was done, who did it, and why.