Set in the future, the plot deals with an undersea tunnel being constructed beneath the Atlantic Ocean which would connect England and the U.S. The special effects lend reality to the effort, showing how air locks shut down critical sections of the tunnel during a disaster and how people are trapped inside forever, as well as other troubles faced during construction. The process is shown to an attentive public via worldwide television and some scenes--such as those showing survivors of an undersea disaster and their relatives grieving at a hospital--are starkly realistic. Dix is the designer of the tunnel who gets to keep in touch with his family only through television or a telephone. Banks provides a willing shoulder for Dix's wife. A futuristic disaster movie with some very real touches.