Phineas T. Barnum and friends finance the first flight to the moon but find the task a little above them. They attempt to blast their rocket into orbit from a massive gun barrel built into the side of a Welsh mountain, but money troubles, spies and saboteurs ensure that the plan is doomed before it starts..
During the troubles in Ireland an IRA bomb plot is hatched to blow up a British power station. Sean Rogan (Tom Bell) is an IRA bomb expert and escapes from prison to try and stop the destruction
Grisly strangulations in London alert Nayland Smith of Scotland Yard to the possibility that fiendish Fu Manchu may not after all be dead, even though Smith witnessed his execution. A killer spray made from Tibetan berries seems to be involved and clues keep leading back to the Thames