The episode starts with Irisa and Jeb Nolan travelling in a vehicle, hoping to drive all the way to Antarctica where they believe there will be as close to paradise as they can get. They witness an arkfall event which when they go to investigate, they discover a sphere but are the attacked by a group of Irathients. Jeb manages to hide the sphere and not loose it to the Irathients. Jeb and Irissa are rescued by law keepers and are taken to the town of Defiance.
Later, Luke is found dead in the woods and Rafe McCawley goes searching for Alak as he believes he killed his son. Jeb is in the pub when the altercation between Rafe and Alak takes place and during a fight, the chief lawkeeper is killed. Jeb volunteers to investigate the murder before anyone else gets hurt. Mayor Amanda Rosewater agrees to Jeb leading the investigation.
Jeb goes to the murder scene and works out what happened. Jeb reveals that the murderer was injured when Luke was killed by a Voltan weapon. Amanda reveals that her Indogene assistant, Ben is walking with the same injury that Jeb believes the killer received and they try to track him down. Jeb arrests Ben but not before Ben's brought the city's shield down.
Jeb and Irissa decide to leave town but when they get a few clicks out of town, Jeb decides to go back and save the town but Irissa decides to continue on to Antarctica.
Jeb and Mayor Rosewater gather the city's populace together to protect the city from an onslaught. The townspeople hide up on the side of the valley to hold the attack for as long as it takes the town's chief doctor, Yewll to get the sphere Jeb found at the start of the episode to work. During the fight, Irissa and some Irathients arrive on motorcycles to help the fight.
During the fight, a Castithan runs off as a coward and Datak Tarr witnesses the cowardliness.
At the end of the programme, the previous Mayor and a mysterious man discuss Ben's failure but why they want the town destroyed is not revealed.