Doctor Pelton is with Layton when he discovers the cannibalism of the murder victim, acting as the coroner.[1]
She is also present with The Notary to put an Access Chip in Bess Till's hand as she is getting upgrade to Second Class by Jinju Seong.
During LJ Folger's murder trial, Doctor Pelton testifies to the brutal castration Sean Wise underwent at LJ Folger and Erik Sotto's hands.[2]
After waking him up from the Drawers, Josie reaches out to her allies uptrain, who in turn reach out to Dr. Pelton. Pelton agrees to give Layton a medical examination to assess the damage done by the suspension serum, but finds no lasting damage or tissue damage; she tells him that he should heal quickly. Layton is wary of her, but she assures him that they are both on the same side, and reveals that there is a blacklist that both of them are on. Shortly after, she allows Josie and Layton to sleep in her chambers, but warns them to ignore the door if anybody comes knocking and to keep it locked.[3]
Doctor Pelton is one of the people Layton recruits into his rebellion. When Layton orders Miss Audrey to call in the people that she trusts, the doctor is one of them. Doctor Pelton argues that Layton wants the same thing that they do and is one of the people that he reveals the truth about Melanie Cavill to. She also helps Josie, disguised as a nurse, to discreetly talk with Miles.[4]
As the rebellion begins, she hangs a piece of red cloth as a signal. Doctor Pelton later treats the wounded following the battle in the Nightcar.[5] She subsequently treats the wounded in her clinic, stating that 37 people have died that she knows of and "god knows how many uptrain." Doctor Pelton then takes care of Winnie after Layton reveals that Winnie's brother is dead.[6]
Doctor Pelton takes part in the meeting in First Class discussing the new regime after the successful revolution.[7]
When Ruth Wardell arrives looking for morphine for Mr. Wilford, Doctor Pelton informs her that they're out as they have treated over a hundred patients. Instead, Ruth ends up having to make do with just aspirin which the passengers make themselves.[8]
When Bess Till arrives to investigate the attack on Lights, she is accosted by Z-Wreck and Strong Boy until Doctor Pelton intervenes on her behalf. Later, while delivering supplies for Doctor Pelton to the Third Class clinic, Zarah discovers that Josie Wellstead is still alive as one of Doctor Pelton's patients, labeled as a Jane Doe.
Later, Doctor Pelton takes part in the scientific summit with Mr. Wilford. Standing in the background, she crosses her arms as she listens.[9]
When Wilford allows the Headwoods to treat Snowpiercer's frostbite patients, Doctor Pelton observes the process and takes an interest in what they're using for treatment.[10]
Dr. Pelton helps Tailies hide from rioters seeking revenge for the deaths of the Breachmen.[11]
Dr. Pelton later takes part in a meeting discussing the deteriorating situation on the train with Roche, Till, Zarah and Layton. Layton asks Dr. Pelton where Second Class stands and she tells him that most of them still back him and they will hold the middle for as long as they can, noting that it's probably why they always get screwed.[12]
After Wilford takes control of the train, Dr. Pelton's files are collected by Jackboots and taken to Hospitality where she is ordered to perform a census on Snowpiercer's population.[13]
Six months after the departure of the Pirate Train, Dr. Pelton pulls Winnie out of class to secretly pass on a message to Ruth Wardell, the leader of the resistance in Layton's absence.[14] She also attended LJ and Osweiller's wedding.[15]
After Layton retakes the train, Dr. Pelton helps Bess Till to rescue Sam Roche and his family from the Drawers. However, they discover that while Roche and his daughter Carly are in stable condition, his wife Anne is dead.[16]
After Asha leaves, Layton spots Dr. Pelton in the mess hall and she tells him that she was sideline for most of Zarah's pregnancy and she's been snooping through the Headwoods' files. Dr. Pelton reveals that the file talks about the scientists performing gene therapy on the baby with some of those processes also being in Josie Wellstead's file too for cold treatment.
Following Roche's attempt to murder Wilford with the suspension drug, Layton calls Doctor Pelton for help. Layton later tells Alex, Bennett and Javi that while Wilford is in critical condition, Doctor Pelton thinks that he will survive.[17]
Doctor Pelton later blocks Miss Audrey from seeing Wilford and she suggests to Alex that she read to Wilford to help stimulate his mind as he comes out of suspension.
When Zarah goes into labor, Layton calls Doctor Pelton to the Headwoods' lab on Big Alice as he doesn't trust Mrs. Headwood and wants Doctor Pelton's help to ensure that Zarah is fine. Doctor Pelton expresses her disgust with the Headwoods and their methods and becomes alarmed when Zarah's temperature keeps dropping. However, working together. Mrs. Headwood and Doctor Pelton are able to keep Zarah stable and successfully deliver the baby. Noticing Layton's injuries, Doctor Pelton asks Bess Till what had happened to him and Till reveals that someone had almost succeeded in killing Layton.[18]
Doctor Pelton performs an exam on Layton, determining that he is showing signs of a concussion from the explosion despite Layton insisting that he's fine. Doctor Pelton warns Layton to take it slow as "that blast really did a number on you," and tells Zarah to make sure that Layton doesn't go to sleep.[19]
After Layton is found unconscious, Doctor Pelton is called and she quickly rushes Layton to her clinic for treatment. Once she has him on a ventilator, Doctor Pelton reports to Layton's friends that he's stable, but in a coma and has been for at least twelve hours. Doctor Pelton doesn't know if he will wake up, although she notes that his pupils are responding despite some brain swelling which is a good sign. Doctor Pelton urges them to stay strong, hold Layton's hand and talk to him. It's a waiting game, but they're welcome to stay. Till leaves followed by Pelton who promises Bennett Knox that she will keep them updated.
After Layton finally regains consciousness, Doctor Pelton expects him to make a full recovery with no lasting brain damage.[20]
After Melanie Cavill is rescued by Snowpiercer, Doctor Pelton rushes Melanie to her clinic for treatment, kicking everyone else out.[21]
Doctor Pelton listens to Melanie and Layton's joint announcement giving the passengers a choice between staying on Snowpiercer or going to New Eden on Big Alice. Doctor Pelton chooses to stay on Snowpiercer, standing holding hands with Miss Gillies and listening to Miss Audrey singing in the Night Car after the separation.[22]