John Locke advises Charlie Pace to keep away from the addiction. Charlie actually feels the positive effects of staying clean. There's a lot happening at the high altitude area where the French signal was first intercepted. Sayid Jarrah, James 'Sawyer' Ford and Kate Austen are trying to build a network with the antennas so that they can get that signal again. Jack's cave caves in and he is trapped. Charlie comes to the rescue. When he saves Jack, he feels he has overcome his heroin addiction.