Catastrophe had visited Earth and left it completely destroyed. But mankind had already bridged the galactic gap and on the planets of the Centaurus system the discovery of the Memory Bank had brought man to the brink of immortality. The custodian of the Bank and ruler of the Centauran council was the most beautiful woman of the Centauran world, thousand-year-old Marian.
Lieutenant-Commander Merck was a non-depositor. He had an intuitive feeling of the danger of the Memory Bank that it would Weaken the people, leaving them easy prey to hostile civilizations. He was to meet the ravishingly beautiful Barbarian.girl Iskra, who was to play a vital part-in his resolve to defy the powerful Centauran culture.
This book was published in 1961, and has very much the feel of the pulp books from earlier times. Earth is gone, and the few stragglers who made it to the Centauri system have stagnated. There are eerie aliens from the Sirius system that have kept the humans contained from traveling elsewhere, and a group of space-faring 'barbarian' humans who had managed to escape to another star system. The Centaurans who chose to live over 1,000 years do this by dumping old memories into a memory bank every 10 years, since it seems that our brains get overloaded and that is why we all die of old age.
It seems something 'from the Dark' is pushing the barbarians back, and so they are fighting the Centauri system people to live there and take it away from the 'degenerate' humans. Of course, the Centauran 'hero' who does not use the memory bank falls for a barbarian girl, and lots of action ensues.