This is the first of the three Inspector Hornleigh films that Fox produced in England from 1939 to 1941. Gordon Harker plays the Inspector who is a keen collector of rare postage stamps. He is disturbed while he is bidding for a rarity at an auction to be given the news that there's been a stabbing at Hendon boarding house in North London. Hornleigh discovers that the stabbed man called Hendry like to keep his room locked for most of the time. The Inspector has to find out what Hendry was keeping secret.
The case develops when it is discovered that the Chancellor of the Exchequer's budget plans have been leaked. This would cause some individual or organization to make a killing on the Stock Market and make a huge dent in Britain's economy. The Chancellor'scase containing the budget plans must have been switched with an imitation case while he was having a meeting at the Pheasant Inn. Hornleigh has to retrace the Chancellor's movements there and to detect who was in the best position to make that switch.
I can't say that any of the characters really took my interest. When the action moves to a leather shop it gets a bit more intriguing. The attack on Sergeant Bingham (Alastair Sim) in an alleyway is another good scene in the film. I didn't guess the murderer and I think it will surprise most people. But I have to say I prefer Gordon Harker's Inspector Elk character in the 'Return of the Frog' mystery.