Enough of this frivolity. It’s curling-up-in-front-of-the- crackling-fire-with-a-good-book...

Enough of this frivolity. It’s curling-up-in-front-of-the- crackling-fire-with-a-good-book time, and the current season is replete with the work of veteran novelists with their built-in followings--those who would queue up, dutifully, for the next offering even if it were printed upside down and backwards. (And, in the off-years, it wouldn’t hurt.)

Always welcome back, however, is the annual offering of ex-jockey Dick Francis with his wry mysteries built around his background on the English racing circuit. And, in Straight (G. P. Putnam’s Sons: $18.95; 324 pp.), Francis explores the problems facing steeplechase jockey Derek Franklin in trying to recuperate from a broken ankle--a common enough injury when a half-ton horse has the ill manners to step on it. Instead of the six-week tedium of daytime telly that he has envisioned, however, Derek finds himself embroiled in the affairs of his older brother, Greville, who is killed in one of those fluke, unpredictable, sidewalk-construction-site accidents.

And, as Greville’s only heir, Derek suddenly is up to his neck in matters completely foreign to him--including his brother’s gemstone business that would seem to be thriving except that everything is in hock because of a large diamond purchase Greville made shortly before his death, but which has subsequently disappeared. Among his other inheritances: a loyal, and not-so-loyal staff attached to the business, a promising race horse acquired by Greville, drawers full of electronic gadgets that his brother loved and, oh yes, Greville’s mistress as well. But why on earth would unidentified people keep trying to do Derek in and, while failing, keep banging up his ankle just as it’s on the brink of healing? Just what in the world was his dead brother--wittingly, or unwittingly--involved in? The denouement is a rouser as Derek, alone and his ankle again in flames of pain, must defend himself against a ruthless killer. “Straight”-- steeplechase language for the homestretch--is a Literary Guild special-feature alternate.

And, in the old reliable department, we can’t ignore the tireless and skilled Danielle Steel who, in Daddy (Delacorte Press: $19.95; 352 pp.), swings off on a refreshingly new tangent in a story that, in less-competent hands, would be a fairly standard chronicle of the unfulfilled modern woman who “finds herself,” and a new career, and splits with her successful husband of 18 years. But, surprise! It isn’t Sarah in her quest to live her new freedom to the hilt who fascinates author Steel, it’s the baffled and somewhat inept Oliver--cut adrift with three unmanageable kids--who dominates the story. And they are “unmanageable kids” simply in the fact that Oliver has always been so self-centered that he would find anybody --saint, sinner or anything in between--equally unmanageable.

Oliver is thrust into personal problems on top of personal problems to which Dr. Spock never addressed himself. But the hapless father--absorbing, perhaps, a little wisdom from his own father who, in his 70s, had to cope suddenly with a dramatic shift in his own life--manages to get his act together in this well-done, off-beat story. Somehow, we know that the resourceful Sarah is going to muddle through successfully even as she remains aloof from the load she has dumped on poor old Oliver. Which, indeed, she does.

Leave it to doctor-turned-novelist Robin Cook to scare us all to death with what can happen in hospitals and doctors’ offices when medical skill and evil become so intertwined that we don’t know where one begins and the other ends. The premise in Cook’s latest, Harmful Intent (G. P. Putnam’s Sons: $18.95; 368 pp.), is exactly the sort of thing that causes thousands of doctors millions of sleepless nights--a routine operating-room procedure goes awry, a patient dies, the lawyers descend, a massive malpractice suit develops, and is won, and a second-degree-murder indictment is lodged. For anesthesiologist Dr. Jeffrey Rhodes, the birth shows every sign of being completely routine until the mother’s vital signs go totally awry; she cramps, writhes, and never regains consciousness.

Disgraced, his professional and personal life a shambles, Rhodes toys with the idea of suicide, but then something more disturbing (if possible) than his disgrace preoccupies him--the possibility that someone, for some reason, had tampered with the medication. Jumping bail, but with a relentless bounty hunter hired by the bondsman on his tail, Rhodes, aided by the nurse-widow of a colleague who, when confronted by a situation parallel to Rhodes’, did kill himself, begins a deadly cat-and-mouse game trying to gain access to the hospital records that might clear him.

This is a real grabber as we sweat out Rhodes’ seemingly impossible job of eluding the bounty hunter, a suspicious hospital employee, then other villains who mysteriously appear; changing his identity, and getting the evidence he needs. At best, there is one--perhaps two--places where the reader can feel safe in laying the book aside to attend to other matters.

With international-intrigue expert Len Deighton at the helm in his Spy Line (Alfred A. Knopf: $18.95; 288 pp.), we’re back facing the knotty problem of how to extricate British secret agent Bernard Sampson from the deadly traps that someone (and, at times, it would seem, everyone ) is digging for him. This is the second of Deighton’s Hook, Line and Sinker trilogy and, in the best “Perils of Pauline” tradition, we last saw Sampson (in “Spy Line”) under a form of house arrest in Germany after having failed to crack the mystery of whatever happened to several millions of pounds missing from the British Secret Service’s petty-cash drawers. Now, however, clearance is given for Sampson’s return to active duty in England--but in a deal with more strings than a tuna fleet. And, once he is on duty, a supposedly routine assignment in Vienna simply underscores the very advice that Sampson once gave to a new recruit: “The more casual the briefing, the more hazardous the operation you are headed into.”

With problems in his personal life--namely his wife’s embarrassing defection to the East Bloc and his adjustment to a new, live-in lover half his age who is trying to mold him to a suburban life style that he hates--the ordinarily imperturbable Sampson needs involvement in another web of international intrigue like he needs another set of eyebrows. Deighton is a master of the veiled nuances, the subtle political infighting and the ever-present suspicion that, somehow, there’s a rat in the most innocent of woodpiles, one that seem to dominate the world’s intelligence communities. With a first printing of 200,000, “Spy Line” is a Book-of-the-Month Club Alternate selection.

Turning author Dean R. Koontz’s imagination loose on an eerie premise is a little bit like dropping a ferret into a brood house. After his latest, The Bad Place (G. P. Putnam’s Sons: $19.95; 384 pp.), readers who thought Koontz’s “Midnight” was populated with weird characters and situations will look back on it as a humdrum excursion into conventionality. For openers, take a man, Frank, suffering from amnesia who finds himself awakening, covered with blood, possessing lots of cash and a couple of unfamiliar identifications, and with strange, unidentifiable objects around him--red gems, black dirt or sand, a giant, dead, rare insect. The usual sort of thing. Frantic, he turns to a young husband-and-wife team, Bobby and Julie Dakota, who specialize in corporate security matters, computer thefts and the like.

Obviously, Frank’s amnesia problem isn’t exactly their bag, but who could resist the challenge? The Dakotas should have. What the team gradually uncovers in the way of weirdos occupying some of the wild portions of Orange County should skyrocket the population of neighboring Riverside County--the strange young man named Candy and his twin sisters, Violet and Verbina, and things that go bump, and worse, in the night. The clutching knowledge that The Bad Place has spawned a Bad Thing that is quietly stalking them all--and that they are powerless to either stop or elude it--grips both the reader and the Dakotas even as the beautiful and tough Julie Dakota, formerly with the Sheriff’s department, tries to pooh-pooh the danger. This is white-knuckle, hair-on-the-back-of-the-neck-curling reading--as close to actual physical terror as the printed word can deliver. “The Bad Place” is a Literary Guild Main Selection.