The evil knight Torchesac, who is at the service of the sinister lord of La Mortaille, gets a very powerful magic flute and uses it for evil purposes. Johan and Pirlouit, assisted by the magician Homnibus, travel to the land of the Smurfs, the only manufacturers of this sort of instrument, to get a new one and battle the usurpers.
| Actor | Role |
|---|---|
 William CorynJohan (voice) | Johan (voice) |
 Michel ModoPirlouit (voice) | Pirlouit (voice) |
 Jacques DynamLa Mortaille (voice) | La Mortaille (voice) |
 Henri CrémieuxHomnibus (voice) | Homnibus (voice) |
 Michel EliasLe Grand Schtroumf (voice) | Le Grand Schtroumf (voice) |
 Ginette GarcinDame Barde (voice) | Dame Barde (voice) |
 Henri LabussièreFisherman (voice) | Fisherman (voice) |
 Georges AtlasSéneschal (voice) | Séneschal (voice) |
 Roger CrouzetLe Schtroumpf #2 (voice) | Le Schtroumpf #2 (voice) |
 Jacques CironLe visiteur (voice) | Le visiteur (voice) |
 Georges PradezLe roi (voice) | Le roi (voice) |