Cause toujours ! (2004)

This way-offbeat comedy from Gallic director Jeanne Labrune concerns two young French women, best friends Léa and Jacinthe. While Jacinthe develops a fixation with the moths that begin to cluster in frightening quantities throughout her apartment, Léa finds herself drawn to a dim-witted fellow employed by a local supermarket, then impulsively decides to follow him home via train. When Léa mysteriously disappears during the days that follow, Jacinthe naturally grows concerned about her friend and decides to investigate.