When Willi's father is abducted and is only released for a valuable statue from his art collection, Tim is the only one who believes Willi that the police are on the wrong track. Together with the smart policeman's daughter Gaby and the highly intelligent outsider Karl, they start to investigate on their own. Against all odds the four discover a conspiracy. In the course of their first big detective adventure they grow together into a committed community, and so Tim, Klöschen, Karl and Gaby become the band TKKG.
| Actor | Role |
|---|---|
 Ilyes RaoulTim | Tim |
 Lorenzo GermenoWilli Sauerlich | Willi Sauerlich |
 Emma-Louise SchimpfGaby | Gaby |
 Manuel Santos GelkeKarl | Karl |
 Trystan PütterKommissar Glockner | Kommissar Glockner |
 Tom SchillingLehrer Pauling | Lehrer Pauling |
 Milan PeschelRaimundo | Raimundo |
 Mai Duong KieuAmanda | Amanda |
 Antoine Monot Jr.Hermann Sauerlich | Hermann Sauerlich |
 Laura TonkeErna Sauerlich | Erna Sauerlich |
 Samuel SchneiderGeorg | Georg |
 Maryam ZareeSusanne Carsten | Susanne Carsten |
 Phil LaudeBienert | Bienert |
 Michou FrieszFrau Müller-Borello | Frau Müller-Borello |
| TTrish OsmondErschreckte Oma | Erschreckte Oma |
 Luna WinterSteffi | Steffi |
| LLeo DomogalskiBen | Ben |
 Pepe TrebsLukas | Lukas |
| ZZeldaOskar | Oskar |
| DDag-Alexis KopplinPolizist | Polizist |