What chapters does Reef start to change?

In Chapter 21, as a result of knowing Leeza, Reef begins to change, as he strives to discover himself. He finishes assignments, and takes care with other jobs he chooses to do for himself. He spent time at rehab not because he had to, but because he wanted to. Reef began to enjoy himself again, to look forward to the next activity.... for the first time since his grandmother's death.