The star dwellers

The inhabitants of Terra nicknamed them "angels". They were exquisitely beautiful, these shimmering, fiery creatures, highly intelligent and playful. Yet they were awesome, too, considering that the youngest were four million years old, and the oldest probably participated in the First Cause which had given birth to the whole universe. Young space cadet Jack Loftus was almost overwhelmed when he had to assume the responsibility of negotiating a treaty with them--a treaty which could mean the life or death of earth and mankind.