"The Mob Doctor" episode "Confessions" opens with Grace and Constantine having a tense meeting at a quiet restaurant. Constantine questions Grace about why she was with Russell King and Franco on Christmas Eve. Grace plays it cool, and says that she was there because Russell was her patient and Franco just happened to show up.
After the meeting, Grace calls Franco to warn him, and learns that Franco is on his way back from Detroit to Chicago. Even though Franco saved Russell's life, he still needs to prove he's an "earner" to get into the crew. Franco brings Russell to meet an old friend who owns a chop shop, but the man won't work with Russell. The Pistons knocked the Bulls out of the playoffs many years back, and he lost a hundred grand on those games. However, when Russell proves he is a true Bulls fan, the chop shop guy arranges to do business with them.
Russell tells Constantine that he's setting up shop, and there's nothing he can do about it. Russell refuses to send a kickback to Constantine's syndicate, and Constantine warns him that a good thief never robs the same house twice. Later, however, Constantine has a hard time convincing his associates to make a move against Russell downtown, because the area is too visible and public.
At the hospital, Grace is paged to see a trauma patient who turns out to be a priest. He has a large infection in his cheek, which he says was caused by a demon after an exorcism. They drain the wound, but when the priest tries to stand up, he collapses. Grace gets cut by a scalpel in the ensuing chaos, and is sent home. Later, the priest freaks out during a spinal tap, and menaces the doctors with a large needle.
Constantine meets up with Nate, and tells him that if he keeps up the good work, the sky's the limit. But when Nate and the gang go to collect from a pawn shop, they find the pawn shop owner dead, their money gone, and a teenage kid running from the scene. It turns out the kid is a witness, not a killer, but Nate and the guys accidentally knock him out, and Grace is called in to attend to the teen.
Back at the hospital, the priest's disease is uncovered: it's rabies, which explains the "fear" of holy water. When Grace was nicked by the scalpel, she was exposed to rabies as well.
It turns out that one of the guys in Constantine's own crew killed the pawn shop owner, just to steal five grand. The traitor levels his gun at Grace, but Nate returns just in time to save Grace and the teen witness. After she almost dies, Grace learns she has been exposed to rabies, and returns to the hospital in time to get vaccinated.
Constantine gets his associates to come around, and they make a move against Russell. After Russell admits defeat, Constantine tells him that the one condition of doing business is bringing in Franco. Russell calls Franco to warn him, and Grace tells Franco to run before Constantine can kill him.