this glitch is also in sic transit. go to the wall from the last glitch and then move down the hall a bit. you have to be weavel. if you go a ways down, you will see a room with a small, brown poll int he right corner, jump at the pole and go into halfturret. may take a few tries but you should go through like the other glitch
(note: you can get here by using the other glitch be just following the solid floor, shoot at the ground to tell what is solid and what is an endless, black void that will kill you. ) doing the glitch this way is esier)