Levinson (with a script by Chris Columbus of Gremlins and The Goonies) uses an apocryphal version of the early life of Holmes as the peg for an adventure which romps with the schoolboy Holmes and Watson through a London predictably shrouded in fog. Less predictably, it is populated by shrieking Egyptian fanatics who use a hallucinatory drug to kill their victims. This plot device is the cue for a series of virtuoso special effects sequences: hat-stands come malevolently to life, a roast pheasant bites back, and the youthful, portly Watson undergos torture by patisserie. It's all a long way from Conan Doyle. But while lacking the clarity and breathtaking speed which Spielberg brings to this type of material, it's agreeable enough entertainment.