Tube Tester is a stop-motion animated film that chronicles a day in the life of a tube tester. The year is 2400. Only one piece of tube testing equipment remains intact and only one man remains who can operate the tester. The operator's time is equally divided between sleep and work. When the operator is sleeping, he rests his head on the tube tester and dreams. When the operator wakes, it's only for brief moments--just long enough to test a tube or refuse services to entities that don't fit into his tester.