The Wright brothers are planning the very first flight in history at Kitty Hawk in North Carolina. Emily and Alexander immediately set off to visit their cousin Charlotte, who lives there, so as not to miss this event under any circumstances. Shortly before the plane takes off, however, two gears suddenly disappear. The two mouse detectives immediately suspect Mr. Richardson, the head of the bird sanctuary, who was against the flight experiment from the beginning. But the case is not as clear-cut as it seems at first.