When Celtics G.M. Danny Ainge traded All-Star forward Antoine Walker in October 2003, the divorce hurt both men. Fans accused Ainge of sabotaging a potential 50-win season, coach Jim O'Brien resigned three months later, and Boston limped to a 36-46 finish. Walker suffered too, bouncing from the Mavericks to the Hawks as his market value plummeted.

That's why it was surprising and sensible for Ainge to reacquire Walker at the Feb. 24 trade deadline. While neither had forgotten the other's insults of 17 months ago--Ainge said Walker had an unhealthy "grasp on the franchise"; Walker called Ainge "a snake"--both have realized that they can accomplish more as allies than as enemies. "Danny had to put his stamp on this team, and there's nothing wrong with that," said Walker last Thursday after he had accepted a shooting lesson from Ainge in hopes of stemming his struggles at the line (55.0% at week's end). "I'm more concerned right now about my relationship with coach Doc [Rivers] because I want to fit in with his system."

Ainge isn't exaggerating when he says, "I see a completely different Antoine." The 6'9", 245-pound Walker is not only in the best shape of his nine-year career but also more interested in playing with his back to the basket than the player who jacked up a league-leading 7.6 three-pointers per game over the last three seasons of his previous stint in Boston. In his first five games since arriving from Atlanta, Walker attempted only 12 threes while averaging a team-high 21.4 points and 9.2 rebounds. The Celtics also went 4-1, giving them a 31-29 record and a 11/2-game Atlantic Division lead over the 76ers. "The two things I didn't know about him were his energy and his competitiveness," says Rivers, admitting that he used to disparage Walker as an overweight three-point shooter. "He's anything but a lazy player--he's actually a hyper player."

In a city dominated by the reigning champion Red Sox and Patriots, Walker's homecoming brought some needed buzz to the Celtics--and renewed the fans' faith in Ainge. In his second full season as G.M., he has already delivered on his promise to transform the franchise, hiring Rivers, rejuvenating the roster with a trio of first-round picks ( Al Jefferson, Tony Allen and Delonte West) and pulling off an Auerbachian heist of Walker for Gary Payton, Tom Gugliotta, Michael Stewart and a first-round pick--then re-signing Payton last Friday after he had been waived by the Hawks. (Ainge pulled the trigger with Atlanta after a deal for Hornets guard Baron Davis collapsed an hour before the deadline.)

Walker's resurgence raises two questions: Why the sudden change at age 28? And is it permanent? "Playing in Atlanta was painful," says Walker, who was 10-43 as a Hawk. "The grass is not greener elsewhere." Walker doesn't want to leave Boston again when he becomes a free agent this summer, but he also doesn't want to accept anything close to a $10 million cut in his current $14.6 million salary. "[We've] got to re-sign him," says Pierce, who has shot 49.2% (up from 44.9%) since his friend's return. "Obviously he makes this team better. Why not at least see what we can do together until my contract is up [in 2008]?"

Before Ainge is willing to commit to three or more years, he must be satisfied that Walker won't revert to his three-launching ways. But Rivers believes that Walker will be willing to remain in the low post to help his team win. "That's who he is now," says Rivers. "I'm sure before the trade [to Dallas] he felt, I can do whatever I want here. I'm Antoine Walker. And then he got traded and realized, Oh, bleep, this is a business, I've got to wake up. Give him credit because he has."