The Vengeance of Li-sin (Large print, Paperback, Large type edition)

Jack Mallory steals a sacred idol from the temple of Tsao-Sun and brings it back to England. It contains priceless jewels, hidden by Chinese priests, and is booby-trapped to explode if tampered with. Meanwhile, Prince Li-Sin tries to kill Jack. A family friend, Dr Hartley, saves him, but will Jack pay a heavy price for his theft: both Hartley and Sir Edward Mallory have received the same threatening letter: 'the vengeance of Li-Sin will overtake you'.