The film has no dialogue. The visual storytelling is accompanied only by poetic inner monologues of the main characters.
First ever film role for Valeria Staskova (Alica Flachova), who is a ballet student. She was 14 when she was cast, and 15 at the time the film was shot.
Both Judith Bardos (Edith Kraus) and Jan Ctvrtnik (Karol Elbert) perform all of their piano parts themselves. The recording was used in the film.
Pianist Edith Kraus (Judith Bardos) passed away at the age of 100 in Jerusalem while the movie was still being shot in Slovakia.
Concentration camp scenes were shot in the Fortress of Komarno (Slovakia). All extras (camp prisoners) are local citizens.