In a futuristic version of Chicago, Beatrice (Tris) Prior lives in a society divided into faction based on aptitude. Abnegation values selflessless, Candor champions truth and justice, Erudite prizes knowledge and intelligence, Amity embodies kindness and forgiveness, and Dauntless epitomises strength, bravery and fearlessness. At the age of sixteen, everyone must choose a faction in which to belong, potentially leaving their families behind and comitting themselves entirely to their new ideology and way of life.
Tris has lived her whole life in Abnegation, learning to be selfless and kind, but she yearns for more than that. At her Aptitude Test, she discovers that she does not fit into Abnegation and that her test results are inconclusive, which is strange and rare in their world. At her Choosing Ceremony, against everyone's wishes, she chooses Dauntless - which is also incredibly rare - and leaves with her new faction to complete initiation.
Dauntless Initiation comprises of a variety of tests involving both physical strength and mental agility, led by the ferocious Eric and enigmatic Four. It is incredibly difficult, particularly for Tris with her weak frame and inability to fight, but failure means being Factionless (without a Faction) and at the mercy of the elements. Throughout these tests, Tris discovers that she is Divergent, which means that she doesn't fit into any one faction and could easily slot herself into any of the five. This makes her a threat that the government - led by the Erudite leader, Jeanine Matthews, seeks to destroy. Tris must keep this discovery to herself or risk being hunted down and being killed.
One night, the Dauntless are given drugs that turn them into mindless soldiers, without thought, feeling or compassion, unable to think or use free will. As a Divergent, Tris is immune - as is Four - but boh must act as though they're under the drug's influence to avoid detection. Ordered by Erudite, the Dauntless march on Abnegation, killing anything and anyone in their path.
Desperate to find her parents, still living in Abnegation, Tris and Four break away from the group to begin their search. This pursuit leads them to be captured by the Dauntless, culminating in a heart-wrenching decision for Tris to protect herself by shooing her friend and fellow Dauntless initiate, Will. With unexpected aid from her Divergent mother, Tris and Four escape, though her parents both die in the process.
In the end, Tris manages to stop the execution of the Abnegation by releasing the Dauntless from the drug's powers, and escapes with Four.
