It is set in the far future, where death, disease, and unhappiness have been virtually eliminated due to advances in technology, and a benevolent artificial intelligence known as the Thunderhead peacefully governs a united Earth.

The notable exception to the Thunderhead's rule is the Scythedom, a group of humans whose sole purpose is to replicate mortal death in order to keep the population growth in check.

[4] In the year 2042, effective immortality is discovered, allowing humans to reset their age while retaining memory.

These revolutionary technologies allowed humanity to triumph over death and ended what is posthumously referred to as the Mortal Age.

Utilizing all of humanity's knowledge and power, the Thunderhead solves climate change, mental illness, and discrimination.

Instead, a group of humans creates the Scythedom, an order of individuals who are responsible for killing ("gleaning") others permanently, unable to be revived by law.

270 years after the Mortal Age, a Scythe named after Michael Faraday visits a house in MidMerica.

Some weeks later, a teenager named Rowan Damisch is attending high school when he encounters Scythe Faraday as well.

Once at the front desk, Faraday reveals that he is here to glean the school's top quarterback, as underage people driving while being intoxicated caused many deaths.

Spearheading the New Order movement is Scythe Goddard, a charismatic man infamous for his cruel mass gleanings.

On the opposition is the notable Scythe Curie, who is well known for gleaning the President of the United States and his cabinet in the early days of immortality as they attempted to cling to power.

Citra says that she tripped a schoolmate down a flight of stairs, which resulted in breaking her neck, and spending three days being revived.

Citra and Rowan are contacted by Xenocrates, who informs them that Faraday committed suicide in order to free them of their apprenticeship.

Meanwhile, Rowan's morals are put to the test as he experiences Goddard's lifestyle, who lives in a mansion he took and has extravagant parties with a posse of New Order Scythes.

Rowan initially hates him, but slowly falls under Goddard's charismatic spell and endures brutal training methods, becoming conflicted over his identity and recognizing the monstrous side he is trying to keep down.

During a party thrown by Goddard in celebration of Rowan breaking Citra's neck, High Blade Xenocrates is present.

During her revival process, the Thunderhead, temporarily free to speak with her, talks to her and expresses concern for the Scythedom.

Instead, Rowan beheads Goddard with his own sword, kills the other Scythes (minus Volta who self-gleaned out of guilt), and burns their bodies, which prevents revival.

Citra, who has been cleared of suspicion of murdering Faraday, struggles, but succeeds in killing her younger brother, Ben.