Margery Louise Allingham was an English writer of detective fiction, best remembered for her "golden age" stories featuring gentleman sleuth Albert Campion. - Wikipedia
Two schoolboys have discovered a miraculous gadget that enables them to read other people's minds. Then one of the children vanishes - and Albert Campion is called in to crack the case. Soon the intrepid sleuth becomes snared in a sinister web of conspiracy, violence, and assassination - and in a lethal power play for control of a devastating device that could shatter the world!