This cut-and-paste exercise combining sex, scandal and scenery in Washington, D.C., has all the suspense of the first half of the ninth inning with two out and none on with the other team ahead 18-1. Only a die-hard baseball fan or a romantic bubblehead would stay glued to his or her seat for the final outcome.

"Lady in Waiting," Gwen Davis' 10th novel ("The Pretenders and "Naked in Babylon" are two others) will find just such an audience: the hopelessly hooked Washington-gossip-junkie and those whose literary development was arrested at Photoplay (any year you like, starting around 1943). To put it another way, if you feel fulfilled by People magazine, "Ladies in Waiting" is your "War and Peace." In fact, "Ladies in Waiting" panders so much to the soap-opera mentality that it could almost be advertised as a do-it-yourself kit showing how to write a marketable potboiler that mixes Tinseltown with the Power Center and never bothers your head for a whole thought. All is titillation, no lating involvement and no final outcome. Perfect!

The pity is, Davis can write creditably when she bothers to, which in "Ladies in Waiting" she seldom does. Instead, she chats us up and slings the slang. On the subject of newspaper salaries, she says, "It was hardly a career for a decent woman when a hooker got that for one throw." She slips in and out of this vulgar vernacular style throughout the book just as she slipped in and out of Washington (via California), circa late Watergate, to soak up local color, pick up a tidbit here, a scrap there, and she admitted as much in a recent interview.

So, while Davis is no doubt chastising herself all the way to the bank, let us have a look at whom and what she has most recently wrought. There is a Tongsun Park character who in "Ladies in Waiting" turns up as a gentleman from Japan named Hiro Takeda (he commits suicide eventually; other characters in the book try but, alas, fail). There is an Elizabeth Taylor character, Gloria Stanley. There is a Sue Mengers super-agent character, here called Louise Felder. And there is a bevy of Washington "types" (as Davis calls them) ranging from a driven, diabolical newshen, Charlotte Dean (a composite of several people, it would seem) to the most boring hero and heroine ever to surface in a Washington novel, the doltishly decent Larry Cochran and his dutiful, do-goody wife, Abby. Abby tells us repeatedly how dedicated Larry (a post-Watergate White House aide) is to his country. (Either Davis found most Washington "types" she met to be square, passive, inarticulate and starstruck, or she imagines them to be.)

Sex, needless to say, rears its obligatory head at fairly consistent intervals. There is this: "His lips trailed clouds of glory down her naked throat."*tWith only the most cursory nod to history in a book about a town that daily creates history, Davis mentions just in passing, by way of setting the scene, that cars outside the White House are honking impeachment and offers us one sad soul who used to work for Nixon but now can't find work. You feel no more for him, pro or con, than you feel for cardboard Chris, the humble but successful writer, as she tries to coax slippery Scott, the reluctant newsman, into an affair (Scott cannot leave his rich wife, Elise, of course):

"We could go make love in the Justice Department,' Chris said. 'Nobody's there anymore.'

"A smile pulled at the corner of his mouth. 'Let's just walk'."

"Why don't we get in a car and go somewhere?'"

"'Elise is using mine. Her Rolls is being fixed'."

Now, if that bit of dialogue does not make a smile pull at the corner of your mouth, you are a tourist. That much I know. You are even more of a tourist if you fail to feel a twinge of pain as Davis keeps referring to a restaurent called the Sans Souci. But little does this tourist-with-a-typewriter care to know or understand the variety and the sophistication that exists in our nation's capital. She wraps up our various life styles into one Photoplay breakfast-time feature: "an aura of light scandal is salt on the morning eggs of Washington." Mayne Davis should have entitled her book "Scrambled Scandal" or "The Morning Eggs of Washington," or even "Pass the Aura." It is to her credit, at any rate, that she passed up "Salt Talk."

At one point, the super-agent character, Louise, says of one Washington "type," "I can't handle all this humility. I'm from Beverly Hills."

Well, Louise, I can't handle this whole book. I'm from Washington.