Lao Chu doesn't take kindly to the man in the black mask's warning that Xiao Guo has no business in a fighting arena. But before he can confront the man, a new cage fight begins and draws everyone's attention. Given the perfect distraction, Xiao Guo tries to use the Black Energy detector, but there's no reaction. Just as they are leaving, the match ends and the winner begins shouting for a fighter called Fire to come face him. Lao Chu realises the best way to find the guy they came here for is to enter the cage himself and draw the man out. In a matter of seconds, he's declared the victor and Fire himself comes to face him. It's the man in the mask.
Still in his office, Chief Zhao is fussing at Xiao Guo, who called with an update on the situation. Yunlan tosses his phone across his desk in frustration and complains to Shen Wei how Chu never respects him as Chief. For a moment, Zhao Yunlan becomes our exposition fairy and explains how Chu was once convicted of a crime and sentenced to penal labor, but Shen Wei brought him to the SID, earning Chu Shuzhi's respect and loyalty. Somehow, these two men turn a conversation about how Shen Wei once sought to use Chu as a spy on Yunlan, into a flirty back and forth that ends with the Chief teasing Shen Wei how fun it'll be to see Chu's face when he learns who the Professor really is. I love these two.
In the locker room of the arena, Lao Chu is preparing for the fight when the man he defeated comes in to beg him to beat Fire once and for all. He tells Chu how Fire tricked his younger brother Jie and gave him a drugged drink so that he would lose the match. Shortly after, Jie committed suicide. Lao Chu promises to take Fire out for him.
Seconds into the match, Fire reveals how he got his name by slinging a ball of fire at Chu's head, clearly surprising him. Xiao Guo begs him to leave the match, but Chu goes in for another try and knocks the mask right off Fire's face. I'm sorry, I love this drama, but the prosthetic makeup here looks like somebody stuck chewed up gum to the side of his face.
When it looks like Lao Chu will defeat Fire, the angry crowd tears open the cage and begins rushing at him. With impeccable timing, Chief Zhao appears and uses his gun to scare the crowd into obedience. As he begins to look into the suspicions disappearances of young men from the arena, Shen Wei follows Jie's brother outside where he confronts Fire.
In flashback, we see that Jie begged Fire to let him win their fight because he needed the money, but since his water was drugged, the fight was over quickly. Outside the arena, Jie was confronted by men wanting their money who beat him when he could not pay. Fire quickly intervened and chased them off, apologizing to Jie.
Fire doesn't bother to explain these details to Jie's brother. Instead, he antagonizes him (I honestly could not find this character's name) until he reveals that Jie committed suicide after the match. Trying to avenge Jie's death, his brother attacks Fire and attempts to light a molotov cocktail to kill him. Shen Wei intervenes, but Fire manages to escape.
Zhao Yunlan and Shen Wei chase after Fire, but they lose him at a crossroads. Lin Jing and Da Qing arrive just in time to offer help and the four men split up in order to tack down both Fire and a mysterious new source of black energy.
Fire is obviously setting a trap as he leaves his bike right out in the open for Yunlan and Shen Wei to find between two warehouses. They enter the building cautiously and Fire immediately attacks. Shen Wei uses his power to restrain Fire and interrogates him about his connection to Purple Wig. Surprisingly, he's never heard of the man.
Boss Zhou sits cowering in the locker room of the arena trying to figure out how to avoid blame for the deaths of the young men he turned over to Zhu Jiu. However, when he begs Purple Wig for help, he's killed instead. Serves him right.
Meanwhile, Fire tells Zhao Yunlan how to find his house. The Chief and Shen Wei realize Lin Jing and Da Qing were taken hostage (yeah, about 15 seconds after they arrived). A small group of young men greet them outside Fire's home and threaten to kill the hostages. But instead of taking the boys seriously, Yunlan chastises Shen Wei about how there are no schools in Dixing. This leads to a hilarious argument between the two over whether or not Yunlan will be returning to Dixing. Can we just add an extra episode or two of these two being this ridiculous? Cause I need it in my life.
The hostage takers grow antsy, so Yunlan lets Fire explain things. Turns out Fire was aware of Zhu Jiu's involvement in the deaths of the fighters who disappeared from the arena. After witnessing one of them die, Fire dedicated himself to saving as many lives as possible. That's why he was drugging them before the fights. If the men lost, they were not targeted by Zhu Jiu. Fire deliberately used his power at the arena so that Boss Zhou would make enough money that he wouldn't want to fire him and Fire could continue to save more men.
While everyone's distracted, Lao Chu and Xiao Guo sneak in and rescue the hostages, escorting everyone outside. Chief Zhao gives Chu and Guo the task of escorting all of the young men to a safe place outside the city.
Elsewhere, Purple Wig gloats to Ya Qiang about how he feels like he has everything under control, but his old injury (from when the Chief shot him in the arm) is clearly causing him pain. When she reminds him they have yet to fulfill their final mission, he indicates he has a remarkable plan.