"The seemingly endless corridors of the Art Deco hospital in WARD 13 are in fact just three 75cm-long modules which clamped together on a metal L-profile slide rail. In many shots, the camera appears to track smoothly with the characters as they run or motor down the corridors. In fact, both camera and figures were stationary, and it was the corridor modules that were moved along with each frame. The size of the movement varied with the apparent speed of the characters. As each module moved out of frame, it was carefully detached from the others and reclamped at the front, perhaps with different model furniture and props or a fake door flat."Definitely worth seeing for the animation in the action scenes.