From the novel's introduction:
'The invention of the "Kay-ray" had opened up unlimited fields by which to benefit humanity; but this was not to be. The inventor's gruesome murder and the capture of the Kay-ray by a ruthless and diabolically clever gang gives rise to a reign of terror which catches millionaires, bankers and ordinary people in its grip. To combat these unprecedented crimes, private detective Clinton Forder and the young scientist Bayne Mandeville need cunning equal to that of their enemies and escape a horrible death by a hair's breadth.'
