To make sure the beam isn't invisible Assassin does the same experiment with the hair as before. If it is OK he will quickly peer through to see what the corridor leads to.
Krusten will first wait to see if Assassin's hair test confirms there is no beam. Once confirmed she will use her super speed to get to the other side before the beam goes back on. She will then check her surroundings thoroughly before moving on.
Assassin will go to where Krusten is now and once there he will try to use his vision to see if he can make out anything unusual about the place.