NASA helps SETI locate the origin of an extraterrestrial radio signal to a human habitat on the far side of the moon. These human inhabitants have lived in a subterranean cave system for millions of years. Their social structure is very unlike that on Earth. Differing from the usual adventure stories dealing with aliens, this science fiction narrative is serious, short and precise and has a novel presentation of technology, philosophy and ideology. The narrative is blended in a mix of interesting concepts for readers of all ages with an interest in science fiction and philosophy. The really remarkable and singular feature of the book unravels as the soft and gentle mannerisms underlying the basic nature of these aliens come to light in the later hapters.