This episode opens with Yukio reminiscing about when he was growing up at the monastery with Rin. Then the scene cuts to Rin and Yukio running up to the monastery which is surrounded by exorcists from the Knights of the True Cross. Inside the monastery are more exorcists and streamers of what looks like webbing. Something had apparently gotten in, and wrapped all of the monks at the monastery in webbing. There is also a note, a threat from the mysterious webslinger stating that he or she would not tolerate anyone who had any connection to Rin and Yukio. The monks were able to protect themselves somewhat, but the exorcists have an eight hour time frame in which to rescue the monks from the cocoons.
Rin of course goes rushing off, wanting to hunt down the webslinger, and Yukio takes off after him. They argue, with Yukio pointing out that Rin should not be running off half-cocked, and Rin voicing his usual complaints about his “younger brother” always bossing him around. (Rin. You and he are twins. It does not really matter that much which of you is older.)
Rin breaks free and manages to get ambushed by the webslinger who is wearing a mask and a hood. The webslinger seals his sword into its scabbard and threatens him. Then Yukio arrives and the webslinger escapes. Rin takes off after the webslinger but runs into Shura who has also arrived at the scene. Shura scolds him for not thinking, but Rin does not really care.
Yukio continues after the webslinger, who leads him to a clock tower. When Yukio enters the building, he encounters Mr. Noihaus, the instructor from previous episodes who has attempted to attack Rin in the past. Yukio sees a bit of webbing on Noihaus’ shoulder and naturally assumes that Noihaus is the webslinger and attempts to apprehend him. Noihaus denies having anything to with the situation, but doesn’t bother explaining himself. There is an altercation and Noihaus escapes.
Back at the monastery, Rin is attempting to unstick his sword, but failing miserably. The webbing has security sealed Rin’s sword. Meanwhile, Yukio reports his suspicions to Shura about Noihaus being the webslinger. Shura says that she had heard that Noihaus had returned to his own country, though she states that since Mephisto was the one who had told her, that the information is automatically suspect. This leads to a discussion concerning the portal that had opened up on the abandoned and burnt out “artificial life” research facility. We learn that Noihaus has a connection to this facility, but Yukio notes that experimenting with artificial life has been forbidden.
Rin decides that he is going to head out to look for Noihaus. This prompts another argument between Rin and Yukio where Yukio points out that Rin can’t defend himself because he doesn’t have his sword, and can’t fight because he doesn’t have control of his flames. Rin of course does not care and tries to head out anyway. This time he does not get very far because Yukio shoots him with a tranquilizer dart. Shura protests, but Yukio is not moved because he is just that determined to protect Rin. He heads off on his own.
Yukio and a few other exorcists head down to the sewers where they track down Noihaus who manages to slip away using a distraction. Yukio takes off after Noihaus, but then he hears a scream and has to backtrack. When he gets back to the other exorcists, one of them has been mummified by webbing.
Then we go back to Rin who is waking up from his tranquilizer-induced naptime. He is extremely cranky and Shura is equally unsympathetic. Rin attempts to head out again, but Shura prevents him. They argue, with Shura pointing out that unless Rin can control his flames, he’s useless. Rin loses his temper, but Shura continues on this theme until it finally manages to penetrate Rin’s thick skull.
Meanwhile, Yukio and the exorcists are reporting that apparently, the webslinger has an accomplice. One of the exorcists is reporting this on the phone when they discover that the webslinger is at the True Cross Academy, and is holding some of the students hostage. Then the scene shifts to the boys dormitory, where Suguro and his friends are attempting to defend themselves against the webslinger. Another scene shift shows us Yukio arriving at the scene, and asking about the situation.
The webslinger’s demands are pretty simple, bring; bring Rin, or the hostages die. Mephisto turns up and starts to use his powers in an attempt to capture or evict the webslinger, but he is interrupted by Arthur Aguste Angel who wants to arrest him for experimenting with artificial life. Mephisto allows himself to be arrested, which leaves everyone else at a disadvantage. (Apparently, Arthur is so obsessed with doing his duty he will actively not do anything about a hostage situation taking place right in front of him.)
Yukio decides to head inside, though one of the other exorcists protests. Yukio however states that he at least wants to find out how many enemies there are, and goes into the building. The exorcist protests he should wait for backup, or at least call his brother, but Yukio does not want his brother to be at the dormitory. Once inside he approaches the room where the hostages are, and manages to overhear the webslinger calling up Rin using Shima’s phone. The webslinger’s plan is obviously to lure Rin to the dormitory.
Yukio attacks the webslinger, but his attack is not as effective as he would have liked. He gets captured by the webslinger, who says that he is going to kill the hostages. More webs are slung, but Rin turns up, along with Shura and some back up. There is a fight, during which the webslinger manages to escape again, after being wounded. Rin burst into flame, which causes some panic for everyone except Shura when she sees that his flame burns the webbing. She yells for him to burn the webbing, which Yukio protests. Rin however seems to be in control, because he’s able to burn the webbing without burning anything else.
The webslinger has a panicky reaction to the flames and charges at Rin, who wounds the webslinger. The webslinger goes out a window and drops. When Shura heads out to investigate, she discovers that the webslinger is a woman. The webslinger wakes up and at the same time, Noihaus appears, aiding the webslinger’s escape. When Noihaus is apprehended, he claims that the webslinger is his wife.
The next scene is Rin, burning off the last of the webbing from the monks. One of the monks is chewing him out because of a few sparks that are dancing around. Rin however is extremely confident and being a bit of a smart-aleck about the monk’s nerves. While Rin is being Rin, Yukio is outside, looking rather unhappy. As he’s sitting, he’s approached by a gentleman who wants Yukio to meet someone. Then we go to the ending credits.
After the ending credits, Yukio is seen getting on a train. In the car is a man wearing a mask. The man introduces himself as Yukio’s grandfather.