The episode begins with Grace arriving to meet Constantine and Constantine confronts her about Franco and Russell King. She explains that King is her patient and Franco happened to be there. Constantine then tells her to inform him that next time she sees Franco. She tells him that she doesn’t want to be responsible for Franco’s death. But Constantine tells her that he wants Franco dead and the next time she meets him, she would inform him. Grace then calls Franco and tells him about her meeting with Constantine. Franco tells her that he is on his way back to Chicago as there is no money in Detroit.
He is planning a way to get King hooked up in Chicago and that way he can also ask for protection. He says that the FBI wants him on the inside; else he is useless to the department. Grace is worried. Constantine assigns Nate his next task. Franco then has King meet with one of his guys, Tony and Tony gives King few jobs that could the King back in the ring. At the hospital, Grace is slightly nervous attending to her next patient. He is a priest and he tells her that he was attacked by the demon while performing an exorcism. Brett arrives as he too is on this case. Grace introduces Brett to Father Doyle and explains the infection. The bite does look human; but they need to check if the infection has traveled to the brain.
Brett finds the whole story amusing; but Grace who is raised a Catholic, doesn’t appreciate the mockery. Constantine meets King and tells him to leave Chicago. King tells him that this is downtown and this is no man’s land and that he would be taking over. Gio, Nate and one more guy go for the pick up that was assigned to them. But things go wrong and Joey, the guy from the store gets shot. A kid runs out of the store and these three follow him. They need to catch him as he knows who killed Joey. But when Gio knocks him to the ground, the kid gets unconscious. Meanwhile, at the hospital, Father Doyle’s legs go numb and he falls down when he tries to walk. Grace tries to hold him and her hand gets cut with a scalpel. Brett orders some tests for the priest and he also tests Grace’s blood; just to eliminate the risk of any infection.
Stafford asks her to take the day off. Nate calls Grace and tells her about the situation. Stafford and Brett are now attending to the priest and Brett collects some spinal fluid. But during this procedure, they happen to discuss about exorcism and demons and obviously the doctors don’t believe in all this. Suddenly the priest gets all violent and tells them that the “devil is real and he is now coming for you”. Next, Constantine meets Celeste and Al Trapani and discuss about taking over downtown. Trapani tells him that downtown is too high profile. Constantine tells him that he is not happy about outsiders like King coming to Chicago and taking over. Celeste and Trapani tell him to forget about downtown as it is too many problems. Grace checks on the unconscious boy.
She finds out that his name is Sam Cooper and he is a runaway from a teen shelter. Also, Sam has asthma. Nate tells her that they saw him run away from a robbery and the store owner was protected by Constantine; and now he is killed and Sam could be a murder witness. Sam wakes up. Gio tries to get answers from him, but Sam has an attack and Grace asks Gio to leave. She then tries talking to Sam, who tells her about his childhood. But he doesn’t tell her what happened at the store. At the hospital, Father Doyle is restrained to the bed. Father Keyes is also present in the room and he tells Stafford, Brett and Doyle that the person Doyle was performing an exorcism on, passed away and he feels that the demon has possessed Doyle.
He is now about to perform an interception. Brett is about to protest but Stafford asks him to let the priests do what they want and the tests can wait. As Keyes sprinkles holy waters on Doyle, Doyle yelps in pain. Brett is shocked. Next, we see that Stavos is talking to Trapani about downtown and on the other hand, Constantine is talking to Celeste. Stavos promises 50% to Trapani and Constantine promises Celeste the same. They both have a deal! At the hospital, Stafford and Brett analyze their present case. They then check the case history of Lisa Dalton; the one who Doyle was exorcising and her COD hasn’t yet been identified. They then see that she was severely dehydrated and that she too had a bite mark on her ankle. It is possible that she was having rabies and was hydrophobic; hence the dehydration.
So when she bit Father Doyle, she passed on this infection to the priest. That is why the priest reacted violently when Father Keyes sprinkled the holy water on Doyle. Brett leaves to get Doyle tested for rabies. But there is one more problem; Grace was exposed to Father Doyle’s blood as well. Brett calls her but Grace disconnects the call. Grace tells Nate to inform Constantine about whatever is happening. Gio is against it and so Louis sends him out to get some food. While he is gone, Nate goes to meet Constantine. Constantine is furious as this becomes kidnapping of a minor. He tells Nate to offer the kid the five grand and ask him to keep his mouth shut. Stafford explains the whole thing to Doyle and Keyes. They feel terrible that they could help Lisa in the right way.
Keyes wants to know if Doyle can be saved. Stafford tells him that the vaccination is effective only before the symptoms manifest. There is a treatment but the odds are slim. They will induce a coma and then tackle with the immune system. Doyle agrees. Stafford orders Brett to find Grace before any of the symptoms manifest. At the house, Sam has another attack and his pump is over. Grace goes and gets a pump she has in her car. She then asks Louis to get some water. She finds some marks on Sam’s neck and realizes that they are new. She asks Sam what happened while she was gone to get the meds. Just then Louis draws his gun on them. Nate arrives on time and shoots Louis. Sam tells Nate that Louis was the one who shot Joey in front of him.
Nate finds the 5k in Louis’ pockets. Next, Nate dumps the body and Grace is worried about Nate and what is happening to him. Brett calls Grace and this time she reaches the hospital and he manages to vaccinate her. Next, Stavos asks Constantine as to what he is thinking by offering Trapani and Celeste 50% each; this leaves them with nothing. Constantine explains that Celeste and Trapani hate each other and so in this case, Constantine will have the full power and eventually all the money. The trio then meets King and King has no way but pay them if he wants to do business in Chicago. But there is one more thing that Constantine wants from him; and this is not negotiable.
He wants Franco. Franco is with Grace and, King calls him and tells him that he cannot protect him anymore. He tells him to get out as Constantine is coming for him. Grace is tensed and asks Franco to leave. Franco doesn’t want to as he just got her back. She insists and Franco leaves. The episode ends.