A former Afterlife Inhuman, JT James was expelled from the community and thus denied the right to undergo Terrigenesis. However, Hive eventually granted him this possibility while recruiting as many Inhumans as possible under his sway, and James took the nickname of Hellfire. Once released from Hive's influence, Hellfire began regretting his condition and became convinced that the Inhumans were a plague for society. He subsequently made a deal with the Watchdogs to help them track down and kill the Inhumans.
Meanwhile, Daisy Johnson had gone rogue and taken the name Quake following the death of her boyfriend Lincoln Campbell. After discovering the existence of the anti-Inhumans group known as the Watchdogs, she resolved to fight them by any means necessary, including violence. Quake eventually figured out that the Watchdogs were getting information about the Inhumans' whereabouts directly from S.H.I.E.L.D. files. Wounded, she called her friend and former colleague Jemma Simmons for assistance. Together, they found out that Hellfire was seemingly the next Watchdogs' target and decided to rescue him.
While waiting for Hellfire, Simmons and Quake argued about Quake's wish to bring him into her fight against the Watchdogs. Hellfire joined them but he soon revealed his treachery: he had helped the Watchdogs hunting down the Inhumans and luring Quake into a trap. When Quake blamed him for being on the side of the enemy, Hellfire confessed that he regretted his condition and had struck a deal with the Watchdogs according to which he would be the last Inhuman to die. Despite her wounds, Quake used her powers to knock over Hellfire and the Watchdogs, enabling Simmons to incapacitate some of them. They hid in a storage box and tried to devise an escape plan.
Hellfire eventually found Quake and Simmons by bombing the iron curtain of the box they were hiding in. The blast knocked them out and Hellfire seized a chain he set on fire to strike a final blow. However, he was stopped by the unexpected arrival of Robbie Reyes, who snatched the chain from Hellfire and decided to use it as its own weapon. After Reyes directed Quake and Simmons to Coulson upstairs in the store, he remained to fight Hellfire, who tossed a bomb at him. However, Reyes easily withstood the assault and took his demonic form to fight the rogue Inhuman.
Upstairs, Coulson and Mackenzie incapacitated six more Watchdogs before finding Simmons and Quake. Simmons told Coulson and Mackenzie about Hellfire's treachery, but before they could proceed further, Ghost Rider and Hellfire fell into the store warehouse filled with fireworks. Quake and the S.H.I.E.L.D. agents exited the store in time while it exploded, releasing a myriad of colored fireworks in the air. The explosion killed all the incapacitated Watchdogs. Immediately after, Ghost Rider walked out the ruins, dragging an unconscious Hellfire on the ground and delivering him to S.H.I.E.L.D.
Following the battle, Quake, the Ghost Rider and the S.H.I.E.L.D. agents went back on the Zephyr One. Phil Coulson came to see Quake and Reyes and told him that S.H.I.E.L.D. needed them despite the fact that they had personal scores to settle. Therefore, Coulson successfully enlisted their assistance in looking for the Darkhold.