A French cultural research group arrives in Finland. From Helsinki, the group travels to Saimaa to participate in Midsummer rituals, where the summer night celebrations overwhelm the researchers.
| Actor | Role |
|---|---|
 Elina SaloMattila - School teacher | Mattila - School teacher |
| EEino KrohnMr. Sedano - professor | Mr. Sedano - professor |
| IIsmo KallioMr. Lang - Sedano's assistant | Mr. Lang - Sedano's assistant |
| NNumidia VaillantSedano's secretary | Sedano's secretary |
| AAulikki Tarnanenthe girl of the raven house | the girl of the raven house |
| LLauri-Juhani Ruuskaneninterpreter | interpreter |
 Kerttu Krohnthe wife of the chairman of the municipal council | the wife of the chairman of the municipal council |
 Leo Jokeladealer | dealer |
| KKari RydmanNot listed | Not listed |