HOUSE OF BLACKMAIL is an updating of the 'old dark house' style of murder mystery with added romance, blackmail, and escaped convict antics. The storyline involves a friendly but ruthless blackmailer (played by Alexander Gauge, well known to audiences for his role as Friar Tuck in THE ADVENTURES OF ROBIN HOOD TV series) who has a foolish young man in his grips. The young man enlists the help of his sister to visit the blackmailer and help pay the debt. She picks up a mysterious hitchhiker en route and arrives at the blackmailer's home to find an assortment of characters present, each with their own hidden motivations.The blackmailer is killed in the middle of the night and the inhabitants of the household cut off until the morning. One of them is the murderer, but which? HOUSE OF BLACKMAIL will reveal all, but not before a running time full of creeping about in corridors, false accusations, the burning of important documents in a grate, and a lot of hold-ups with guns have taken place.This is a pretty entertaining little movie that offers up nothing we haven't seen before, yet it somehow works thanks to a fast pace and a focus on the mystery aspects of the story. There's no time for slow-moving romances and the like here, just a script that keeps you guessing. William Sylvester does well as the protagonist mixed up in the proceedings who may or may not hide his own murky motivations, and Mary Germaine is a pleasingly modern heroine. Denis Shaw's butler stands out, listening at keyholes and keeping racy pictures plastered to his bedroom walls. The ending is unsurprising but ties up this little mystery quite neatly.

Mary Germaines brother has bounced a cheque for 200 pounds.Alexander Gauge decides to blackmail him for 5000 pounds.He goes to Germaine for help.She arranges to go down to see Gauge at his isolated house. On route she picks up Sylvester.Over the radio comes a warning about an escaped convict. Germaine offers Gauge a cheque but he will only agree if she will stay the night.Sylvester goes to look for the cheque but it has gone and Gauge is found murdered and the phone wire cut.There are a number of suspects as Gauge had 2 staff and 2 associates. Sylvester fakes an escape and goes looking for the cheques with surprising results. Germaine brother turns up and is sent for the police.Then Sylvester reveals the actual killer in a less than thrilling climax.