Jean (Laura Dern) is the one who killed Duane (Scott Caan; Susan Ivey's brother) and she used a mold of Frank's (Steve Martin) teeth to put the bite marks on Duane's body. Frank and Susan (Helena Bonham Carter) find the mold of teeth at Jean's house and then they follow her to the clinic. At the clinic, Jean and Harlan discuss the next step of the plan. Her plan started out when Harlan "harassed" her but all this time they've been plotting against Frank. The plan was for Harlan (Elias Koteas) to find a junkie (Susan) and tell her about Frank's clinic and all the drugs.. but the plan went a bit wrong when Duane went along with Susan, since he's a maniac. The junkie that Harlan would lure to the clinic would then steal and sell the drugs, Frank would go to jail and Jean would be next in line to run the clinic. At the clinic, Jean and Harlan argue; she kills Harlan and his murder ends up being recorded on the clinic dental camera thing (that little camera that Frank uses with patients to see an image of their mouths on a monitor). Jean leaves the clinic after killing Harlan and in comes Frank and discovers Harlan's body. Frank fakes his death by pulling out all his teeth and putting them in Harlan's mouth and torching the clinic. The only evidence left is Frank's teeth and a recording of Jean killing Harlan, in which his face is not seen, so the authorities believe it is Frank who is killed (thanks to the camera and because the place where the recordings are stored is fireproof). Jean goes to jail. Frank and Susan move to somewhere in France and he writes a book called Novocaine using his brother's name. Susan is pregnant.