Frank Herbert

Planet Dune has been destroyed; only pockets of resistance remain with the opposition mainly from the Bene Gesserit co-ordinated from their still undiscovered home world. Chapter House. There is a new Scattering being planned and they still hold one asset which has not fallen into enemy hands: they have sandworms, offspring of one giant worm that was rescued from Dune before the end, and in the specially prepared desert they work to turn it into a wasteland.  Book 6 of series.

Paul Atreides has been succeeded by his twin children Leto and Ghanima, under the regency of his sister Alia. But all is not well in the Empire; a harsh tyranny has been established under the fanatical direction of the Fremen disciples. On Arrakis itself, much has changed. A slow ecological transformation has brought vast areas of greenery and even stretches of open water. The sand-worms are vanishing and this spells disaster for the planet.  Book 3 of series.

Set in the distant future when planets form part of a Galactic Empire, two great dynastic families are locked in a bitter feud. The Duke of Atreides has been manoeuvered by his enemy, Baron Harkonnen, into accepting the job of administering the planet of Dune. It is a vast desert where a drop of water is worth a fortune. It is also a planet of vast wealth because it possesses a drug prized throughout the galaxy.  Book 1 of series.

Paul Atreides is the religious and political leader of the Galaxy and was raised to his exalted position by a holy war, fought in the spaceways and on a thousand planets. He has been trained in arcane disciplines by the Bene Gesserit sisterhood and he has superhuman powers. When the order is no longer able to dominate the man they have made a god, they set out to overthrow him. But Paul, able to foresee their plans, resolves to shape them to a shocking goal...  Book 2 of series.

Arrakis, the barren desert planet, is now a green and hospitable world. The giant sandworms are gone and there is only one link between the world and its epic past: the grotesque figure of Leto Atreides, son of the prophet Paul Muad'Dib and now the virtual immortal God Emperor of the Galaxy because he holds the sole ingredient which confers longevity. But his final victory, to produce a species that can outwit him despite his prescient vision, means his own death.  Book 4 of series.

The wheel of history has turned full circle: the deserts have returned to Dune and with them the giant sand-worms. The death of the Tyrant Leto II triggered the release of a swarm of sand-trout, the earliest stage in the sand-worm cycle. They and their descendants have reversed the ecological miracle which changed Rakis (as Dune is know known) from a burning desert to a verdant, pleasant world.  Book 5 of series.