It is a hot summer day and the Song Festival rehearsal is underway for the kokle ensemble. The exhausting rehearsal is enlivened by the arrival of percussionist Reinis. The ensemble's soloist Zane feels that this fateful encounter strikes not only the strings of the kokle, but also the strings of her heart. After the rehearsal, at the school where everyone is staying overnight, Zane realizes that her instrument is missing. It is the eve of the concert, and in the morning they must go to the final grand concert. She asks Reinis for help, as he is the last person to have seen the instrument. As the two wander through the school's dark corridors, it begins to seem that perhaps they will find more than just the lost kokle.