A thriller in six parts by Nigel Kneale.
Suppose an experimental rocket were sent 1,500 miles above the Earth to make certain observations and then to return. The operation should take only a few hours, at enormous speed. But suppose through some defect in the control system the rocket veered off course and were lost for a considerable time. Suppose after it had completed a vast ellipse of hundreds of thousands of miles into the unknown, control were regained, and it landed. What travellers' tale might then be told? Or what might happen?