The Canadians have discovered a valuable substance called Compound X, which can cure infantile paralysis. When a country at war with Canada learns that Compound X also contains magnetic properties that could aid them in their warfare against the British, they send agents to infiltrate Canada and steal a large quantity of the substance. It's up to Sgt. King (Allan Lane) and his Mounties to track down the agents and put an end to their scheme.
Allan Lane
Robert Strange
Robert Kellard
Lita Conway
Herbert Rawlinson
Harry Cording
Bryant Washburn
Budd Buster
Stanley Andrews
John Davidson
John Dilson
Paul McVey
Lucien Prival
Norman Willis
Tony Paton
John Bagni
Earle D. Bunn
Tommy Coats
George DeNormand
Curley Dresden
Douglas Evans
James Fawcett
George Ford
Bud Geary
Alan Gregg
Sam Harris
Bob Jamison
William Kellogg
Walter Lowe
Ted Mapes
Dave Marks
George Plues
Wallace Reid Jr.
Loren Riebe
Dick Simmons
Cy Slocum
William Stahl
Denny Sullivan
Al Taylor
Duke Taylor
Ken Terrell
Charles Thomas
Richard Travis
Dale Van Sickel
Frank Wayne
Robert Wayne
Bill Wilkus
Al Thompson