Henkka Virtanen finds evidence of a possible crime on his way to school. With his friend J.K. Kivimutka, the boys decide to investigate what has happened, because these criminal cases are the responsibility of the detective agency they have set up. When it turns out that mailboxes in the area have disappeared during the night, the detective bureau has already two crimes to solve. A fun and exciting adventure begins, in which the boys also have to face their own fears.
| Directing | Väinö Weckström | Director |
| Directing | Jarkko Felin | Director |
| Writing | Kalle Veirto | Novel |
| Production | Jani Tiihonen | Executive Producer |
| Production | Jarkko Felin | Executive Producer |
| Production | Väinö Weckström | Executive Producer |
| Production | Katriina Tuliainen | Consulting Producer |
| Camera | Italo Moncada | Director of Photography |
| Editing | Jarkko Felin | Editor |
| Sound | Sami Virkki | Sound Designer |
| Costume & Make-Up | Nina Korento | Costume Design |
| Crew | Erika Messo-Karhu | Choreographer |
| Camera | Joonas Niemi | Best Boy Grip |
| Costume & Make-Up | Riikka Felin | Makeup Designer |
| Art | Amadeu Vives | Production Design |
| Sound | Torsti Spoof | Original Music Composer |
| Writing | Jarkko Felin | Screenplay |
| Writing | Väinö Weckström | Screenplay |
| Lighting | Kari Niemi | Gaffer |
