He's the star of TV's most popular comedy, one that makes millions for CBS and Warner Bros. He's also an addict who desperately needs long-term help. Inside the struggle to keep Charlie Sheen alive and working.

After Charlie Sheen reportedly trashed a room at New York City’s Plaza Hotel in October and looked frightfully underweight when he returned to the set of Two and a Half Men following his holiday hiatus, Warner Bros. TV and CBS had decided that enough was enough. Sheen — the star of the immensely popular and profitable sitcom — was in serious need of help. But offering to shut down production on Men so the actor could seek treatment for substance abuse wasn’t so easy, no matter how much critics accused the studio and network of enabling their 45-year-old star. Not only was Sheen denying that he had a problem, he continued showing up for work, and doing his job well. ”We sat in so many meetings where we all thought, ‘None of us ever had to deal with something like this,”’ says one key insider. ”There’s not a playbook we could go to and follow the steps.”

On Jan. 28, the studio and network finally got the call they were hoping for. After a reported 36-hour bacchanal in his Beverly Hills mansion that resulted in a heavily publicized trip to the ER for abdominal pains, Sheen agreed to undergo a personalized rehabilitation program in private, away from a traditional rehab facility. The decision put Two and a Half Men on hiatus, leaving some 300-plus crew members out of work and CBS with a potential hole in its Monday-night schedule. Sheen’s manager Mark Burg has already publicly predicted that his client will return to the set by month’s end, but only the studio and Men creator/executive producer Chuck Lorre can decide when production should resume. (A studio source says no decision has been made. Lorre declined to comment for this story.)

As tough as it was to get Sheen back into rehab, it’s going to be even tougher to decide when to pull him out. Thirty days of private treatment doesn’t make much sense for a guy who’s battled drug addiction for years (see timeline). But Men — which is averaging 14.6 million viewers in its eighth season — commands $210,000 for every 30 seconds of ad time and sold into its second round of syndication for an estimated $1 million per episode last year. And the show can’t continue without Sheen. How can CBS and Warner Bros. balance what’s best for their star with what’s best for business? Says the insider, ”What we’ve learned is that until he makes a decision that he needs help, we have to go about business as close to normal as one can get, under these circumstances.”

In 2003, Lorre and Lee Aronsohn, a former co-writer on Cybill, were developing a comedy about a misogynistic playboy whose nephew and sad-sack brother move in with him. Almost immediately, the producers set their sights on Sheen, who was coming off a career resurgence after replacing Michael J. Fox on Spin City. Even then, Sheen’s demons weren’t far behind: Five years earlier, the actor was hospitalized for a near-fatal accidental cocaine overdose, which prompted his father, actor Martin Sheen, to hold a press conference asking fans to pray for his son. That incident resulted in Sheen’s second trip to rehab, but in 2006 actress Denise Richards filed for divorce from Sheen amid allegations that he was gambling and abusing prescription drugs and porn. Yet the actor’s personal woes never damaged his public persona. That same year, Men remained TV’s top comedy with 15.5 million viewers, who clearly enjoyed watching Sheen play a PG-rated version of his party-boy self on the small screen.