The famous forensic phonetician Matthias Hegel is a luminary in his field. Even the slightest deviation in the sound of a voice is enough for him to distinguish truth from lies and thus convict criminals. But now the police consultant confesses to having committed a gruesome murder.

Alma manages to obtain a job as a court painter with the bourgeois prince Philip, passionate about botany. When he sees a portrait of her sister, the beautiful Christine, he immediately falls in love. But the Baroness has plans for her own daughter. Fortunately the faithful Shaky is still here.