Enclosed - ACE377.2

Two young women throwing stones from a vertical lift bridge. Playing on the tracks inside it. The gate swings shut and they find themselves shut inside. Watched on CCTV by man who starts whispering messages through a loud-hailer and making noises with air horns. Man starts bridge mechanism and the central section begins to rise, separating the two women. Man playing wild music. Woman below tries to find a way up. The man continues to makes noises. Woman above calling for help. Man playing searchlight on them as the other continues her climb. She slips and falls into the river. The other is caught in the searchlight. Credits.