After the series grew in popularity, he began to write more entries for it, later collecting the short story and initial five novellas in the omnibus book Wool.

[4] By March 2013, Howey had signed a print-only deal for around US$500,000 (equivalent to $650,000 in 2023) with Simon & Schuster, to distribute print copies of the initial collection, Wool, to book retailers in the US and Canada; he turned down $1,000,000+ offers from publishing houses to retain full rights to continue distributing Wool online, noting that he had already earned more than seven figures from his online publishing royalties.

Three years ago, Holston's wife, Allison, became convinced that the outside world was livable and that the IT department, which runs the external sensors, had deceived the rest of the Silo.

Following Holston's death, Mayor Jahns and Deputy Marnes embark on a trip to the Mechanical zone, the Silo's lowest level, to interview Juliette Nichols, their top candidate for sheriff.

Juliette agrees to become sheriff on the condition that she is permitted to perform long-overdue mechanical maintenance, which requires a power blackout, and Jahns assents to the plan.

Bernard is incensed by the blackout and Juliette's appointment and poisons Marnes's canteen on their way back up, resulting in Jahns's death.

He also trains a man named Lukas to become his successor and teaches him the secrets of IT: the IT department is the true power in the Silo, and records of knowledge from the old world have not been lost but confiscated and sealed in a hidden chamber.

Bernard finally finds a pretext to condemn Juliette to a cleaning, but one of Juliette's friends in Mechanical, Walker, secretly arranges for her protective suit to be made out of quality materials, unlike all previous protective suits, which were secretly designed to fail and constructed of intentionally defective materials.

Inside, she encounters a middle-aged man calling himself Solo, who explains that this is Silo 17 and he is the last survivor of an uprising decades ago.

In 2049, freshman Congressman Donald Keene is recruited by Senator Paul Thurman for the CAD-FAC (Containment and Disposal Facility) project, ostensibly an underground repository for the world's nuclear waste to be constructed in Fulton County, Georgia.

Donald, who has an education in architecture, is tasked with designing a self-sustaining shelter, a Silo, that will be built near the CAD-FAC for facility workers to use during emergencies.

Donald and Thurman are present for the opening ceremonies when a nuclear blast destroys Atlanta, and they and other attendees are ushered into the CAD-FAC.

Thurman reveals that CAD-FAC was a cover for World Order Operation Fifty (W.O.O.L), an initiative to preserve humanity in the event the species was threatened with extinction.

They are managed by Silo 1, which houses Operation Fifty co-leaders Thurman, Erskine, and Victor, and other key personnel such as Donald.

Major rebellions are treated with "resetting", the population is reduced, the remaining residents are given amnesia-inducing medication, and the computers are wiped.

Donald is awakened on Thurman's orders to find a solution after Victor, the mastermind behind Operation Fifty, commits suicide.

Thurman and Erskine divulge to Donald that they headed a conspiracy that instigated the nuclear apocalypse and justify their actions as protecting humanity from annihilation by nanotechnology.

Donald detests his involvement in Operation Fifty, but he continues cooperating since the fate of humanity depends on the Silos' success.

The tunnel breaks through to 17 just as Thurman notices that 18 has gone rogue and orders its termination, and only about 200 residents make it to safety before 18 is saturated with deadly nanobots, claiming the life of Lukas.

Meanwhile, Juliette discovers that all Silos possess a tunneling machine that, when activated, will connect them to a place designated "Seed".

Silo 17's machine requires more fuel than is available, so Juliette and a group of willing survivors try to walk to Seed over the surface using modified pressurized cleaning suits and oxygen tanks.

It is revealed that the Silos are enshrouded by an artificial veil of toxic dust that is likely formed by nanobots, but beyond them, there is breathable air, clean water, and a thriving ecosystem.

A reviewer for Wired praised the initial novellas, and their collective Wool omnibus, while also noting that their publication "clears away the grime of the past and reveals the new truth" about changes in the publishing industry.

Film rights for the story were sold in May 2012 to 20th Century Fox, and director Ridley Scott and Steve Zaillian were named as producers.

[24] By the time Kindle Worlds shuttered in 2018, 122 novels, novellas, and short stories set in the Silo universe had been published via the platform — the third most for any of the licensed series.