Dumarest saga

The series started with The Winds of Gath which was published as an Ace Double in 1967, bound back to back with Crisis on Cheiron by Juanita Coulson

Dumarest of Terra is a 33-volume series of science fiction novels by Edwin Charles Tubb. Each story is a self-contained adventure, but throughout the series, Earl Dumarest, the protagonist, searches for clues to the location of his home world, Earth.

The stories are set in a far future galactic culture that is fragmented and without any central government. Dumarest was born on Earth, but had stowed away on a spaceship when he was a young boy and was caught. Although a stowaway discovered on a spaceship was typically ejected to space, the captain took pity on the boy and allowed him to work and travel on the ship. When the story opens in The Winds of Gath, Dumarest has traveled so long and so far that he does not know how to return to his home planet and no-one has ever heard of it, other than as a myth or legend.

It becomes clear that someone or something has deliberately concealed Earth's location. The Cyclan, an organization of humans surgically altered to be emotionless (known as Cybers), and on occasion able to link with the brains of previously living Cybers (the better to think logically), seem determined to stop him from finding Earth. Additionally, the Cyclan seeks a scientific discovery that Dumarest possesses, stolen from them and passed to him by a dying thief, which would vastly increase their already considerable power.

Also appearing in many of the books is the humanitarian Church of Universal Brotherhood. Its monks are spread throughout many worlds as are the Cyclan, the two being arch-enemies—which does not make the Church Dumarest's ally, but in some instances they support each other.