The Partner is Santa-san

Shigeko Ishikawa is being stalked by an unknown man. While Kogoro investigates, Conan is forced to watch over her two-year-old son nicknamed Santa. Ishikawa is later kidnapped by the unknown man and Conan investigates Santa's home in order to search for clues. Conan finds a feather of a White-eye and learns that Santa has been giving away figurines to people in the neighborhood. Conan realizes what the culprit's motive is after learning about the endangered counterpart of the White-eye, the Black-eye; He asks Santa to take him to the man who received the White-eye. Eventually ending at an abandoned pet store, Conan confronts the culprit and reveals that the culprit was intending to sell the endangered Black-eye to the underground economy and kidnapped Santa's mother when he perceived the White-eye figurine to be a threat. Conan clears the misunderstanding and explains Santa gave him the figurine as a friendly gesture.