Mr. Bean: The Animated Series

Upon leaving a jigsaw puzzle from Mrs. Wicket's attic unfinished due to a missing puzzle piece, Mr. Bean goes on an elaborate treasure hunt which starts inside Mrs. Wicket's fireplace and ends inside a small shack in the park. Upon arriving in the shack Bean finds a key, runs home, opens the box containing the last puzzle piece with the key and joyfully solves the puzzle.