Ever since fall, Charlie's Angels has been in decline. From the halcyon days of Farrah and Kate, when its ratings share reached a celestial high of 67, the show's Nielsen altimeter had plunged into the low 30s. Two weeks ago the last-hired Angel, Shelley Hack, became the first fired. "They can say I didn't work out, but it isn't true," she protests. "What happened was a network war. A business decision was made. Change the time slot or bring on some new publicity. How to get publicity? A new Angel hunt. Who is the obvious person to replace? I am—the new kid on the block."

Her equanimity is remarkable, given the brutal botching of her dismissal. On Valentine's Day all of the show's principals got a telegram inviting them back next year—except Shelley. Unaccountably, she did not learn of her dismissal until a day later, when her press agent got the word from a reporter. "It's disgusting the way this thing was handled," an ABC executive concedes. "Everything was so premature and ugly." Indeed, ABC was still refusing to confirm the firing last week—"to let her save face," one co-star theorized, but there was also a pragmatic motive. "We've still got three shows to go this season," the network aide admitted, "and it's going to be pretty awful—the last one is a two-parter which Shelley is very involved in."

One regular on the set suggests that Shelley's downfall was a sagging "Q" (likability) rating with viewers. Johnny Carson blamed other letters of the alphabet. "It's supposed to be a T&A show," he gibed in his monologue last week. "When Hack's A is put where her T should be, it still doesn't jiggle." Some feel she may have been sandbagged as the cool intellectual in a jiggly extravaganza. "I was supposed to play the Intelligent College Girl from the East," laments Hack, a 1970 graduate of Smith. "Maybe that type didn't fit into Charlie's Angels." Some would argue Shelley never had a chance: Her first real speaking part came in the program's fifth week, and the first show that centered on her didn't air until just before Christmas. "In January I got letters saying, 'Glad to see you're talking,' " she says. The real bottom line, speculates Hack, was the overall reemergence of CBS plus the Angels' NBC competition, Diff'rent Strokes. "The networks are concerned about each other's gains," she says. "What is CBS gaining with? The shows are clever, better. Never underestimate the American public."

Her colleagues say they will miss Shelley. "I hate to see her go," says Cheryl Ladd. "I really don't understand the decision." David (Bosley) Doyle seconds that: "Cheryl, Jackie and I feel we've all been lucky to be friends with someone like Shelley." Yet Hack, 32, leaves with no regrets. "It's been fun," she says. "I had seen Charlie's Angels before I signed on, and what can you say—it wasn't Shakespeare. There are other things I want to do." Among them: writing a memoir about it all; traveling to China and Tibet; finding a new house to share with sister Shawn, 23 (she has a new man since her breakup with writer-producer Nicholas Meyer, but isn't ready to name or move in with him)—and searching for a meaty film role. "Very possibly," she observes, "success in Charlie's Angels may be in inverse proportion to success in films." Very possibly indeed. One Angel candidate recently overheard discussing the vacancy with co-producer Aaron Spelling at lunch: Farrah Fawcett.