In the future, man has created a way of travel that literally tunnels through the very molecules of the solid earth itself. This is all accomplished in TAU-mode shuttles. But when a shuttle becomes encased deep within the Earth's crust, the only way to rescue it's passengers is by using a fantastic, experimental LAMBDA-mode shuttle. Unfortunately, even it's designer has no real clue as to whether it will succeed, or whether it's pilot can keep from going mad during the mission. A very thought-provoking British TV feature.