Mrs Vanderlyn

In the short story The Incredible Theft, Mrs Vanderlyn is a beautiful blonde American woman. She has been involved in some dubious spying and espionage in which she uses her charms to seduce her victims into telling her their secrets.

According to Charles Mayfield she has been married three times. To an Italian, to a German and to a Russian.

Portrayals
In the ITV adaptation it is revealed that she had seduced a young tank officer into revealing secrets of a secret tank which caused him to commit suicide; at the end she hands over to the Germans a copy of the stolen metal formula [which in fact had been changed to be unworkable] after she blackmailed Thomas Mayfield with a Japanese contract in which he sold howitizers to the Japanese.