This has something of the "Rumpelstiltskin" to it, only it's not straw into gold, it's sugar into diamonds! "Dennison" (Dennis O'Keefe) is on the trail of some thieves who stole a fortune in US treasury bonds and are heading to London to do a deal with the gem fakers. His arrival sees him allied with "Insp. McClaren" (Philip Friend). This policeman is also working on a more sensitive case involving a nuclear scientist - and it just so happens that his daughter "Marline" (Margaret Sheridan) is wearing a brooch with one of the Wonka-jewels in it. As we discover who made it, the threads of the story start to come together - but who is pulling whose strings? It's a bit long and takes a while to get started, but once the wheels are in motion it's not a bad little thriller with some magical science (courtesy of Paul Hardtmuth) and a bit of menace from the usually reliable Francis de Wolff. It's all production line stuff with themes based on already well used, adequate acting and predictable plot-lines , but it is watchable enough.