Bolygónkat, 30 évvel a votanok inváziója és a Föld terraformációja után, az ember mellett más idegen fajok népesítik be. Joshua Nolan-t és földönkívüli fogadott lányát, Irisa-t a sors furcsa fintora vezeti el Defiance-ba, az egykori St.Louis városába, ahol most emberek és votanok élnek együtt békében.

Nolan és Irisha, apa és lánya hamarosan két család viszályába keveredik és egy gyilkosságba, amely mind előszele egy hatalmas inváziónak.

While investigating vicious Hellbug attacks, Nolan & Irisa realize they are tied to Irathient spirit raiders that have come into town. Meanwhile, Irisa starts experiencing strange visions.

Kenya is kidnapped. Rafe learns that Luke was involved in some mysterious goings-on at the mines and orders Quentin to get to the bottom of it.

Amanda and Nolan take a transport across the badlands to transport a prisoner and join forces with a band of outlaws. A visitor to Defiance must make Irisa confront her traumatic past.

An old war buddy catches up with Nolan at the same time a Castithan criminal with a history of violence enters the picture.

Interesting relationships develop when the residents of Defiance are forced to stay indoors as a threatening Razor Rain storm approaches. Meanwhile, visions lead Irisa to the Spirit Riders and Sukar, who has fallen under the influence of a strange and mysterious force.

Following the big storm, Nolan and Tommy find an American astronaut who has been in an induced sleep for the past several decades.

A deadly plague threatens the town; racial tensions rise when the Irathients, who are immune to the virus, are quarantined.

The town of Defiance is shocked when the remains of a leading businessman who went missing almost six years ago, are discovered hidden in the walls of the NeedWant.

Amanda’s mayoral campaign is threatened when Nolan is involved in an accident on the eve of the election, prompting the town to question Amanda’s decision to appoint him as Lawkeeper.

The citizens of Defiance prepare to cast their votes for mayor; Nolan’s past violently rears its head; Irisa must decide whether or not to embrace her destiny.