 They also realize that all the rooms in which the murders took place have windows on the front of the building, and that when the exterior positions of the windows are lined up together according to which floor they are on, they correlate to 11 notes in the chorus of the song "Calendar Girl".This enables them to identify where "The January Man" will next strike.Nick sets a trap with Bernadette as bait, outfitting her with a neck guard to prevent the killer from strangling her.