Stranger in a Strange Land
Episode 9 of Season 3 is number 56 of 82 and is a Jack episode. In the off-island flash back we see him vacationing in Thailand where he meets a mysterious (is there any other kind on this show?) local woman who helps him fly a kite, has sex with him, looks into his soul and she tells him he is a leader and a great man, but this makes him lonely, frightened, and angry and he makes her tattoo Chinese characters on his arm to that effect.
On island he strikes a bargain with Ben that he will help doctor his now infected back to prevent further damage he is prevents Juliet from being executed for killing someone while helping Sawyer and Kate escape. One of he others who speaks Chinese tells Jack his tattoo means, “He walks amongst us, but he is not one of us.”