An underwater expedition gets abducted by a society who has lived below our seas for eons. They observe our surface societies, with an occasional above surface flight in what we call UFO's. They have no crime and collect suface artifacts which have been found at the bottom of the sea and placed in their museums. Two of the surface crew members accidentally kill a young girl and man then try to convince everyone it is time to leave. Does anyone know the title to this book and/or movie?? Help?