A really good episode dealing with Charlie. In this episode, the flashbacks don't really tell us too much that we don't already know. We know that Charlie was a rock star, and we know that he is addicted to drugs. However, it does show how he got into those drugs, which is really interesting to see.
We also get to see him on the island, trying to figure out his role, and trying to deal with his withdrawls. This was also a really nice addition to the episode, and added a lot to his character.
Also, we get even more moments with John Locke trying to help Charlie with his drug addiction. These moments were great, and added a lot to both Charlie and Locke.