The Sherlock Holmes Game

Agents of the notorious Professor James Moriarty have stole the crown jewels! Your assignment, Sherlock Holmes, is to find them so they may be returned to the Tower of London. Each player has a dual role, first as Moriarty, hiding the Jewels, then as Holmes, searching for them.

This is "another", and earlier, Sherlock Holmes game made by Cadaco. Players hide a magnet under the game board then switch sides. Each player uses cards and die rolls to move around the board and use a small clear round plastic container holding a metal ball to locate the "hidden gems" that the other player placed under the board.