Defiance townsperson Dalton Taggart drives out to the forest and puts on an expensive pair of running shoes. The Irathient Spirit Riders drive by, whopping it up, and Dalton glances at them briefly as they go on their way. He then starts jogging through the woods, but soon realizes that something is closing in on him beneath the brush. It finally grabs him and drags him away, screaming.
Irisa is exercising on the roof when she sees a butterfly land on her knife as she freezes in one position. When she glances away to see the Spirit Riders drive into Defiance, the butterfly disappears without a trace. Meanwhile, Sukar and Rynn tell the other bikers to get their supplies while they look around. Rynn stops at a booth and picks up a fruit from the merchant. He tells her that she has to buy it, and says that he lost his brother to the plague that the Irathient brought to Defiance. Rynn licks the fruit and puts it back on the tray, and the merchant starts to grab her. Irisa arrive and throws a knife into the table, and advises him to drop it. She walks off with Rynn and Sukar, and Sukar repeats his invitation for her to join the Spirit Riders. Irisa refuses and Rynn notices Irisa's badge. When the younger Irathient says that she wears it because of Nolan, Rynn dismisses him as weak.
Before Irisa can respond, she gets a call from Nolan over her hailer. He calls her out to Bissel Pass where they've found Taggart's body. When Irisa gets there, they confirm that something chewed up his body beyond recognition and drained all the bone marrow from his body. As Tommy and Nolan look around, Irisa notices the same butterfly from before, perched on a tree, and gets a sudden flashback to a human with a knife attacking an Irathient woman. Meanwhile, Tommy finds the shoes and confirms that they belonged to Taggart.
Sukar visits Amanda in her office and notices that she has keepsakes from all of the races except the Irathients. She invites him to make a donation and then warns him that the townspeople have complained about the Spirit Riders. Amanda assures him that his people will always be welcome in Defiance as long as she's mayor, but Sukar points out that she's up for re-election. When Amanda offers to put the past behind them, Sukar warns her that the past is always with them. However, he agrees to assimilate, if for no other reason than to learn their weaknesses for the day when Defiance turns against his kind.
At Need Want, Kenya is indulging the sexual preferences of a masochistic client, Boyd Bowen. They start to have violence sex and he screams the safe word over and over... and a large insect burrows out of his chest, killing him. Nolan, Tommy and Irisa arrive and bring Yewll with them, and the Indogene confirms that the creature was a Hellbug, a mutant insect that feeds on bone marrow. Nolan knows about them from past experience and is sure that once they kill the nest matron, the drones will turn docile.
Irisa sees a tattoo on Boyd's arm and gets another flash of the human attacking the Irathient woman, and the human has the same tattoo. She quickly leaves the bedchamber and Nolan goes after her out to the bar. He asks if she's still having flashbacks brought on by post-traumatic stress, and Irisa admits that they've been getting worse since they came to Defiance. Tommy and Yewll come in, having found a Hellbug egg purse in the alley. Yewll reports that she scanned the bedsheets and found an organic compound on Kenya's bedsheets, and that it was also on Taggart's running shoes. Nolan realizes that it's an attack pheromone and that someone placed it to kill both victims.
That night, the Tarrs invite Christie to their home since Rafe is still angry with her. She tries to cook a traditional Castithan meal and Datak complains about it in Castithan. Christie storms out and Alak angrily tells her father that his fiancee has been learning to speak their language. He goes after Christie while Datak complains to Stahma that Alak hasn't learned to control his future bride. His wife assures him that their son will learn, but reminds him that they'll need to resolve the differences between Rafe and Christie so that they can marry her into their family... and gain Rafe's mine holdings.
Alak apologizes to Christie about his father, but she points out that at least he's there for her and that Rafe didn't come to dinner at her invitation. Before they can pursue the matter, a Hellbug burrows out of the ground and advances on Christie. Her screams bring Datak and Stahma, and Datak draws his energy blade and dares the Hellbug to attack. Another one emerges and he takes them both on, while Stahma gets Alak and Christie out to the street. A minute later, Datak comes out, covered in bug slime, and says that perhaps they should dine out.
The Tarrs take Christie home and tell Rafe what happened, insisting that Alak was the one who saved Christie. Rafe reluctantly thanks them while Nolan and the others arrive. Yewll confirms that Christie's clothing has been covered with the Hellbug pheromones and they figure that Rafe and his family were the killer's next targets. Rafe vaguely remembers that he dealt with both Taggart and Boyd in a land deal ten years ago and Nolan insists on going over all the property records.
The next morning, Nolan, Rafe, and Tommy are still going through the records. They finally locate the deed and Irisa sees a photo of the farmland. She realizes that it's the farm in her visions and hallucinates the photo bursting into flames. She drops it and runs outside, and Tommy goes after her. Meanwhile, Nolan confirms that originally an Irathient, Julluh Grisu, owned the property in the West Valley. Rafe says that he had no idea how Taggart and Boyd obtained the land from Julluh. Tommy comes back in and admits that Irisa threw him to the ground and drove off in a roller. Nolan follows her to West Valley, where she's having another vision. This time she sees three Irathients--a mother, father, and daughter. The father collects butterflies. Irisa picks up a discarded knife and realizes that Boyd and Taggart were the ones who killed the couple... and that their daughter, who escaped, is Rynn.
When Nolan and Irisa return to Defiance, Irisa refuses to see a doctor to treat her visions. They go to Need Want to find Sukar, who says that he doesn't know where Rynn is. Irisa tells him that she saw the murder of Rynn's parents, and he realizes that she has been touched. Sukar explains that Rynn always claimed that she didn't know who murdered her parents. He then suggests that he show Irisa how to open her heart to the visions so that she can see the present as well as the past, and find Rynn.
When Irisa agrees, Sukar and his gang begin the ritual. Irisa manages to look back through time and get a clear vision of Boyd and Taggart approaching Julluh and his wife Ket. They demanded that the Irathients sell their farm, and when the Votans refused, the two humans attacked and killed them. Rynn managed to escape, running off into the woods. Irisa then focuses on the present and sees Rynn going into an old abandoned mine shaft.
As Nolan and Irisa head to the mines with Tommy and Sukar, Nolan apologizes to Irisa for doubting her. She angrily blames him for making her afraid of being an alien, and says that it's too late for them to work out. They go to the mine and descend down the shaft in an elevator until it grinds to a halt. Sukar tells the no one is to harm Rynn. When Nolan points out that's up to her, Sukar tells him that he would understand if he were a good parent.
The posse leaves the elevator and discover that the floor is covered with Hellbug excrement. They wipe themselves with it to mask their smell but realize that the matron isn't on that level. When they get into the elevator, Tommy tries the controls and they short out, dropping the car down several hundred feet. It comes to a halt and the posse finds thousands of Hellbugs flying and crawling around. The Matron, an enormous Hellbug several stories tall, approaches them but fails to pick up on their scent. Tommy works on the controller while Irisa plants charges to seal off the tunnels.
As Sukar starts searching for Rynn, she steps out of the shadows and shoots him in the leg. She's holding a bottle of the attack pheromones and threatens to throw them on the group, triggering another attack. Nolan warns her that the Hellbug nest will soon grow big enough to wipe out Defiance, but Rynn doesn't care. Sukar tells Rynn that Irisa has the Sight and used it to lead them there, but she doesn't believe him and dismisses their gods. Irina tells Rynn that she saw the entire thing and that her parents have been avenged. She asks if Rynn is willing to kill the town to further avenge her parents, and Rynn says that she is. The Irathient rolls the pheromone jar at them but Nolan catches it while Irisa wounds Rynn in the shoulder with a throwing knife. Nolan then throws the jar onto the matron, shattering it, and gets everyone into the elevator. As the Hellbugs attack their matron, Nolan shoots the charge and sets it off just as Tommy gets the elevator working.
Later, Amanda holds a ceremony granting the West Valley farmland to Sukar and his people. As a gesture of cooperation, Sukar then leases it back to Rafe. Rafe and Sukar shake hands, and Christie hugs her father, saying that she's proud of him. Once the ceremony is done, Sukar goes to see a captive Rynn... his daughter. He tells her that her parents are dancing with her ancestors, and insists that the gods spoke through Irisa, showing her the correct path. Rynn points out that she's going to prison because of the "correct path," and her father admits that he doesn't have the Sight and doesn't know for sure.
As Nolan and Kenya leave Kenya's bedchambers, they see Irisa at the bar. They watch as Sukar sits down and talks with her.
Rafe walks Christie to the Tarr home. She runs to Alak, who is waiting for her, and Rafe waves to her. Intent on her love, Christie doesn't notice him.
Rynn sits in her cell, alone.
Irisa tosses and turns in her sleep. Nolan sits at the side of her bed and holds her hand.`