Black Hearts in Battersea

"Simon paid off the driver and turned to follow Mrs Twite. But she seemed to have locked the door behind her and, as he rattled the latch unavailingly and then rapped the locker, something dark and suffocating was forced down over his head and 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 ...