The Secret of Jack O'lantern

There was another death to mourn. The teacher Joseph Ross. Holmes and Watson found the crime scene identical to that of Mrs Hughes the day before, with the exception that instead of five pumpkins, only four were arranged around the corpse. Holmes thereupon feared that, following the pattern, one would have to reckon with at least three more bodies in the coming days. It was essential to find the perpetrator as quickly as possible. But a dream of Dr Watson's made everything appear in a new light...