Drooping ratings and alleged bookkeeping scandal aside, the real life-or-death problem for Charlie's Angels is keeping television's most tantalizing triangle equilateral. When Shelley Hack joined Farrah Fawcett and Kate Jackson in the Angel alumnae club this spring, the replacement assignment fell to Lynn Stalmaster, 50ish, known in the trade as "the master caster." Stalmaster and his vice-president, Toni Howard, spent five weeks testing more than 2,000 contenders in five cities, searching for an Angel who was "more of a street girl" and less of a model type. The choice agreed on finally by the producers and ABC was an off-Broadway-trained beauty, Tanya Roberts, 25, whose tresses have been tinted auburn to set her apart from blond Cheryl Ladd and brunette Jackie Smith. "Tanya had the right vulnerability," explains Stalmaster, "and she has a provocative figure."

"Lynn definitely has an eye," enthuses Tanya, whose 5'7½" physique will help put the jiggle back in the series. "He'll go with someone who doesn't have a name if they're right." Indeed, this year's Angel also-rans (depicted at right) shouldn't lose heart. Stalmaster's initial rejects are filed in his elephantine memory (and his company's filing system), and he has been known to retrieve them later for major roles.

He did cast John Travolta from the start in ABC's Welcome Back, Kotter. ("Before Lynn, no one really knew who John was," says Travolta's manager, Bob LeMond.) For the role of Gabe Kaplan's wife, however, Stalmaster passed over Farrah Fawcett. But he did pluck LeVar Burton out of USC for Roots, rescued Christopher Reeve from obscurity in 1978's Gray Lady Down for Superman, and went against type ("I detest that word") to cast singer Mac Davis as a pro football quarterback in last year's North Dallas Forty. "In the final analysis, it usually comes down to only one or two actors who can really bring a character to life," says Stalmaster. "I don't discover anybody. I only bring them to the attention of the filmmakers. Yet I derive a lot of warm satisfaction from knowing how well some of them are doing now.

"My pattern through the years has been to take as much care with one line, or even an important reaction shot, as with the lead roles," continues Stalmaster, who gave one line to Richard Dreyfuss in 1967's The Graduate (and later cast him in The Apprenticeship of Duddy Kravitz), four lines to Jon Voight in 1967's Hour of the Gun (pre-Midnight Cowboy) and got Jill Clay-burgh her breakthrough job in the 1975 TV movie Hustling. "It really doesn't matter if you do the small roles as long as you're in the right company," he maintains. "An actor can make something wonderful out of a small part. Directors crave that kind of invention."

A lawyer's son, Lynn started in the business as an actor after graduating from Beverly Hills High and earning an M.A. in theater arts from UCLA. Though he had only middling success in finding parts in the 1950s, Stalmaster got useful experience. "I know what it's like being rejected," he smiles. In 1958 he opened his casting shop, persuading the producers of Gunsmoke to gamble with fresh faces. Since then he has cast such TV properties as Roots, Family and Three's Company. ("He's the best person to test with," says John Ritter. "He acts instead of being a wooden reader of lines.") Movies and made-for-TVers are now Stalmaster's preferred line of work—he has cast more than 400. He won't discuss fees, but the going rate is $6,000 to $20,000 per film.

Lynn's staff (now six and all women) once included his ex-wife, Lea, who has since become a veep at Twentieth Century-Fox. Stalmaster sets aside time to visit his kids Lincoln, 14, and Lara, 12, but regrets that he so rarely sees friends like Voight or director Hal Ashby. "My primary outlet," says Stalmaster, who drives the requisite black Mercedes 450 SLC, "is tennis."

But the job does have its perks. Since finishing work on A Change of Seasons (with Shirley MacLaine and Bo Derek), Stalmaster has turned to the upcoming thriller Looker. "Now," sighs Lynn, still recovering from his Angel hunt, "I've got to go look at another bunch of beautiful women."