Gate Haven - Hall of Obscurity - Episode Trivia - Post-Traumatic Slide Syndrome The climactic showdown in PTSS is a little trickier than your average double scene. Both professors' faces are clearly visible, so one can't be a stunt double. They physically interact with each other, so there can't be a split screen at work. So how'd they pull it off? Well, the following freeze frames make it painfully apparent. John Rhys-Davies' face was superimposed on his stunt double's head... and the moment the stunt double starts moving, the effect falls apart. For additional fun, check out this video clip (297K) of the Amazing Arturo and his Magical Sinking Neck!  Gate Haven - Hall of Obscurity - Episode Trivia - Post-Traumatic Slide Syndrome