When Pratt is witnessed bringing a gun into the emergency room, Carter feels compelled to defend him. However, Pratt's erratic behavior makes Carter reconsider. Meanwhile, Weaver hopes to keep her pregnancy a secret, but physical complications might compromise her plans. Lewis warily watches self-destructive patient Chip Mealy, who admits to molesting young boys. Romano warns guilt-stricken Kovac not to admit to a grieving mother that his miscalculation caused her son's death. Chen treats high school students who overdosed on Ritalin. And Gallant confronts the scheming young wife, Koko, of an aged, dying man.