Well if you really want to catch this one you should be really careful not to miss it. Fast forward to when the Reveran decides to take revenge on the Bordello. This is the part where he comes in to kill the vampires. If you skip to the scene of the Medieval Torture room in the wh*re house you come to a part the reveran is going to free the blond girl. The blond girl then turns into the red-head lead vampire. When the strecther is being pulled upright you see the blond girl, not the red head for like half a second.