“Dust” is a dystopian science fiction novel by Hugh Howey, and is the sequel to his novels “Wool” and “Shift”. Dust picks up where the events of Shift left off. Donald Keene’s health has declined dramatically as he tried to find a way to save the other silos, while Charlotte continues work on a modified drone to see what exists beyond the silos. Meanwhile, Juliette organizes the miners and diggers of Silo 18 to tunnel their way into Silo 17, where Jimmy, a young couple (Rickson and Hannah), and several children, including Elise, wait for contact with 18. Juliette’s silo contains many residents who are wary about digging through the wall of their silo, but Juliette tells them they have nothing to worry about because she has been to the outside and survived.

Keene continues to struggle with the entire concept of the silo system, which he unknowingly helped design. Intended to save humanity from nanoterrorism, Keene has learned that the fifty silos that have preserved humankind for 250 years so far will be scientifically computed and considered in another 250 years. The silo with the greatest chance of survival will be released back into the world, while all other silos – including Silo 1 – are exterminated. Keene races against the clock to prevent this from happening, attempting to talk Juliette through things.

However, one of the masterminds of the silo project, Senator Paul Thurman, is awakened. He is both enraged and saddened to learn what Keene has been up to. He has Keene arrested and brutally beaten. Juliette’s dig succeeds in breaching Silo 17 just as Thurman realizes 18 has gone rogue. He gives the extermination order, in which poisonous gas is pumped into the silo. Some 200 people manage to escape through the tunnel to Silo 17, with the tunnel being sealed behind them. The nearly-5,000 people still in 18 are all killed. Juliette blames Keene, unaware of what has happened.

Charlotte works to complete the drone, and establishes contact with Juliette. Juliette wants nothing to do with Charlotte, believing her to be part of the hierarchy that entrapped humankind in the silos. Charlotte is then confronted by a Security agent named Darcy who has figured out that Charlotte had been illegally awakened. Naturally curious, Darcy thinks there is something big going on. Charlotte explains everything to him, during which time he agrees to help her get Keene out of his holding cell. Keene tells Charlotte he is too ill to flee the silo, but that she and Darcy must go instead. Keene will stay behind to detonate a bomb which will destroy Silo 1, and which will give all other remaining silos a chance to escape. Darcy ultimately dies defending Charlotte’s escape, while Keene detonates the bomb and destroys Silo 1.

Studying a facility map with others, Juliette discovers that each silo has a digging machine directed toward a specific place called “Seed”. They tunnel out from Silo 17 to discover blue skies and green growth, while a computer-controlled veil of dust has been erected around the silos, completing the lie of a destroyed world. Juliette, Jimmy, and the survivors follow the map to a massive concrete bunker stocked with food and supplies – as well as seeds – to begin civilization all over again. Charlotte comes across them, and is invited by Juliette to join them. Juliette has realized the truth about Charlotte and her brother. At little Elise’s suggestion, the people decide to head north to water so that they can fish and settle.