Poke and Pena, two private investigators in debt, see an advertisement in the newspaper about Dr. Peltonen's disappearance and the promised reward for finding him. The boys retreat to investigate the case in a house they have rented in the countryside, which happens to be next door to the criminal gang that kidnapped the doctor. The gang's boss, 'Synkkä' (Gloomy), and his sister, 'Kaunotar' (Beauty), try to distract the boys by hiring them to guard their villa.
| Actor | Role |
|---|---|
 Pentti ViljanenPena | Pena |
 Oke TuuriPoke | Poke |
 Ville Salminen'Synkkä' | 'Synkkä' |
 Kirsti Hurme'Kaunotar' | 'Kaunotar' |
 Ossi ElsteläHamara | Hamara |
 Uljas Kandolin'Arpinaama' | 'Arpinaama' |
| RRafael KarimaNot listed | Not listed |
 Aku KorhonenJosé Carillo 'Harry Brown' | José Carillo 'Harry Brown' |
 Kauko KäyhköNot listed | Not listed |
| VVarma LahtinenNot listed | Not listed |
 Aarne LaineMr. Wilkins 'Don X' | Mr. Wilkins 'Don X' |
| UUolevi LönnbergNot listed | Not listed |
 Tauno MajuriNot listed | Not listed |
| SSirkka OsmalaPeltonen | Peltonen |
| RRafael PihlajaDr. Peltonen | Dr. Peltonen |
| IIrja RannikkoNot listed | Not listed |
| VVilho RuuskanenNot listed | Not listed |
 Unto SalminenRatas | Ratas |
 Heikki SavolainenNot listed | Not listed |
| HHarri SinijärviNot listed | Not listed |
| SSeija SoraDr. Mrs. Peltonen | Dr. Mrs. Peltonen |
| VVeikko TyrväinenNot listed | Not listed |
| UUrho WestmanNot listed | Not listed |
 Kaarlo WilskaNot listed | Not listed |
| KKauno Laine(uncredited) | (uncredited) |
| PPaavo Sovijärvi(uncredited) | (uncredited) |
| UUuno Andersson(uncredited) | (uncredited) |