Well, this is a sad one. It's Kennedy and Heidi, the 18th episode of Season 6.  Christopher finally got clean, but it took a car accident to get him there. High again with Tony in the car, Christopher nearly hits two teenage girls and flips his new car. Tony gets out of the car, but has had enough and suffocates him. Paulie's mom or aunt -- whatever -- dies, too. But no one cares. AJ has a crisis on conscience and goes all Rodney King on his therapist.