Cartman's Mom is Still a Dirty Slut

Dr. Mephisto is about to reveal who Eric Cartman's father really is! Glass shatters and gunshots ring out. A mysterious assailant apparently shot Mephisto while the lights were off. Much to Eric's chagrin, they rush Mephisto off to the hospital. Chef rushes out the door with Mephisto in hand. They must fight against time to learn Eric's background, who is his father? Where does he come from?