" Simon paid off the driver & turned to follow Mrs Twite But she seemed to have locked the door behind her & as he rattled the latch unavailingly & then rapped the locker something dark & suffocating was forced down over his head & a pair of hands gripped his throat" Simon coming to London to study painting with his old friend Dr Field finds he has vanished without trace Determined to discover what lies behind his disappearance Simon is trapped in a fiendish plot Why has his landlord got guns in his cellar & how does one deal with his irrepressible daughter Dido ?