The Mysterious Mystery!

Little Adelbert, son of a wealthy family, is kidnapped and held for ransom. The gang, led by Mickey, are quickly on the case. Mistaking Detective Jinks as a 'suspeck', the gang captures him and notifies the police, who recognize the detective and release him. One of the kidnappers gives the gang a dollar to deliver a package to Mr. Wallingford: A ransom note attached to a pigeon. The note tells the Wallingfords to attach (5) $1000 bills to the pigeon, but the kids accidentally let the pigeon escape. Riding with Mr. Wallingford, the gang goes to an airfield and hides from Det. Jinks in a plane that Mr. Wallingford hires to follow the pigeon. During the flight the pigeon lands on the wing and Joe wing walks to retrieve the bird, but drops it. The pilot tries to rescue Joe, but falls (safely into a body of water), leaving Mickey to fly the plane. Mickey, along with Joe and Farina, manage to follow the pigeon who returns to the barn where Little Adelbert is being held. With Mr. Wallingford and Det. Jinks following the plane, Mickey crashes into the barn, where the kidnappers are pinned underneath the rubble. Mickey handcuffs the crooks as Mr. Wallingford arrives, who tells Det. Jinks to make sure the boys get the cash reward for capturing the kidnappers. As Mr. Wallingford hugs Adelbert, the gang runs away with Det. Jinks in pursuit, waving the reward money at them. - IMDb