Christie Tarr (née McCawley) is the only daughter of the town’s most influential citizen, Rafe McCawley and is in a relationship with the son of her father's biggest rival.
Christie grew up without her mother because her mother tried to feed Christie and her brothers rat poison when they were children. Christie then took on a motherly role in the family, acting as caregiver for her father and brothers.
As of the first episode, Christie is in a secret relationship with Alak Tarr, son of her father's biggest rival, but this relationship is revealed when Alak becomes the suspect in her brother, Luke's, death. Christie reveals that Alak could not have committed the murder because he was with her all night.
Christie and Alak are eventually married despite their parents' ongoing feud.
Early in the season, Christie learns she is pregnant with Alak's child. They are happy about the news, but not everything is easy.
Treasure Doll & Castithan Cosplay
One day, Christie goes to the arch looking for Alak, but finds Deirdre Lamb instead. Christie complains that she never knows where Alak is. Sensing Christie feels lost, Deirdre offers to help her find her mojo again. Christie takes the opportunity to vent to Deirdre about how hard it is living with Castis who treat her like an outsider. Deirdre then introduces her to a club where humans dress up like Castis, and they form a friendship. Christie finds she feels powerful while dressing up like a Castithan, and Deirdre encourages her to continue.
When Alak finds out that Christie is going to this club and that she has received a courtship gem from another man, he is deeply offended that she is disrespecting his culture and their marriage. He then goes to the NeedWant where he begins an affair with Deirdre.
At first, Christie is oblivious to the affair and remains friends with Deirdre, but when Deirdre attempts to induce a miscarriage in Christie, Christie kills Deirdre by throwing her off the arch. Stahma then gets a scapegoat to confess to Deirdre's murder, allowing Christie to go unpunished. Christie then tells Alak, "You're a Castithan male. I know you have needs, but you must never again let them threaten our child."
Return of Pilar
Christie's mother, Pilar, returns to Defiance and has an emotional reunion with her daughter. Pilar attempts to convince Christie and Alak that their child will never live comfortably in a town controlled by the Earth Republic (as Defiance was at this time). She proposes that Christie and Alak move with her to a place called the Harmony Collective where humans and Votans live peacefully together. They even have horses. Christie's brother, Quenten, is skeptical, so Pilar takes charge and forces them to go with her. She knocks Alak out and forces Christie into the car at gunpoint.
Alak, Christie, and their baby, Luke, are being held in Pilar's old cabin in Oklahoma city with little means of escape. Datak, Stahma, and Rafe are on a mission to rescue their children, but when they arrive, they encounter a rogue faction of the Votanis Collective, lead by Rahm Tak. Datak and Stahma must pretend to be on the side of the Votanis Collective, a believable lie as they have a long history of loyalty to the VC.
When they arrive at the house, Rahm finds Christie hiding in a closet and kills Rafe in front of her. Speaking in Castithan, Christie shouts, "You’re all devils! May Rayetso consign your soul to solitude and fire! May your liro stink of unclean death in the forever-after of the Three Hells!" Rahm is offended that Stahma would teach a human these words and forces Stahma to choose between killing her and Datak. Knowing that Luke will be found if Rahm is not satisfied quickly, Christie offers her throat to Stahma, stating she is not afraid. Stahma slits her throat, and Christie dies next to her father.
Christie, Alak and baby Luke were held against their will by Christie's mother Pilar, while Alak and Pilar were checking the traps, the Votanis Collective came to the house with Rafe, Stahma and Datak, Christie took Luke and hid, her brother died trying to protect them, however she was discovered and her father was killed tying to save her by then she and Stahma realised the only way to keep Luke safe was for Stahma to kill her daughter in-law, Alak watched his mother kill his wife and after the V.C left, Alak and Pilar went inside and found Rafe and Christie's bodies and soon heard Luke crying the three of them then left to find some where safe to spend the night.