John Strang has a violent altercation with the father of his fiancee, a man who Strang knew was responsible for embezzling all his money. The next day the man is found dead from a gunshot. Strang joins with Special Branch to track down the real killer, a case which will throw Strang into the counter-espionage arena as he battles Nazi spies out to steal Strang's new revolutionary aircraft design.
[Note: there is no misprint here. This is not exactly the same synopsis as that of .]