Morning's Dream, Night's Song 4 Episode 8

Reinhard von Müsel and Siegfried Kircheis revisit the location of Karl von Reifeisen's death to look for new clues. A falling bag of flour which almost crushed Reinhard gives him a brainwave and he quickly asks Kircheis to confirm something for him. Soon after that, he and Kircheis report their findings thus far to Geahard von Steger, the principal of their alma mater, and insinuate to him that the murderer is Moritz von Haase and even summoned the latter to prove his colour-blindness. However, this is just a ruse to make Steger reveal that he is the actual perpetrator.