Basil--famous sleuth of mousedom--lived in the cellar of Sherlock Holmes' house. A devoted admirer of the great detective, he had learned his craft by listening at the feet of Holmes himself. The Mystery of the Missing Twins was one of the strangest cases in Basil's career. He had only a few crumbs of clues with which to find solutions to such baffling questions as: Who had masterminded the plot? Where were the twins, Angela and Agatha, being kept?