Fall is traditionally a season in which new books are as plentiful as pumpkins in shop windows; 2006 is no exception. There has been the customary onslaught of what the publishing industry like to call “big books,” meaning those that sell enough copies to pay the rent for a long time (both for the author and his or her very happy publishing house).

Here are some of the big books I’ve read since the clocks were set back:

1. “Under Orders” (Putnam, 320 pages, $25.95) by Dick Francis, his first novel in six years, and it’s definitely a winner. It rewardingly features Sid Halley, the jockey forced into retirement when a horse fell on him (not as uncommon in English racing as on American tracks), and whose hand is then crushed, sending him into a new career as a private detective.

This fast-paced thriller opens on Cheltenham Gold Cup Day, which turns out to be an excitement-filled afternoon: A racing fan drops dead, a victorious horse collapses immediately after its race, and the winning jockey is shot to death in the parking lot. Although Mr. Francis turned 86 on October 31, he is no doddering old-timer. The new novel incorporates such contemporary phenomena as DNA testing and Internet gambling.

The triumph of “Under Orders” is a joy to behold for reasons having nothing to do with the book itself, which is in a dead heat with any of his previous best-sellers. Since Mr. Francis is too kindly a gentlemen ever to raise the issue himself, I’m not, so I will.

A malicious idiot named Graham Lord wrote a biography of Dick Francis titled “A Racing Life” which was published only in England. In it, he made the outrageous claim that Mary Francis, Dick’s wife, actually wrote the novels for which her husband received such international acclaim. In scores of interviews, the author generously stated that his wife deserved a dual byline for her contributions to the books, which mainly took the form of research and, later, editorial assistance.

After his wife died in September 2000, Mr. Francis averred that he was finished with writing. His son, Felix, persuaded him to have another run. Let’s hope Mr. Lord has someone read it to him.

2. “The Mission Song” (Little, Brown, 352 pages, $26.99) by John le Carré is a novel one can respect, even admire, yet fail to enjoy. Told from the viewpoint of a naive translator, it is largely set on an isolated island, the scene of an important meeting in which the representatives of various countries and African tribes double- and triple-cross each other as they seek to enrich themselves at the expense of the poorest people in the world.

The sheer elegance of the prose elevates and almost salvages the book, which is essentially the minutes of a complex meeting.

3. “Wild Fire” (Warner, 519 pages, $26.99) by Nelson DeMille, which is to Mr. le Carré’s book what a ride on the Cyclone at Coney Island is to a lengthy stroll through the old masters wings of the Metropolitan Museum of Art. A chilling plot (a right-wing plan to annihilate a hefty portion of the Islamic world by precipitating a nuclear Armageddon), a familiar hero (John Corey, who is fearless, competent, and hilarious), his gorgeous, frequently exasperated FBI agent wife, and a NASCAR-like pace that won’t let you stop reading combine to provide the most fun you can have in a public place.

4. “Hundred-Dollar Baby” (Putnam, 304 pages, $24.95) by Robert B. Parker is another in the long-running (more than three decades) series featuring Spenser, one of the greatest private eyes in the history of that noble genre, and it’s exactly what you’d expect it to be. If you order a porterhouse steak, or a glass of Veuve Clicquot, or unwrap a Mars bar, you know what you want and you’re happy to get exactly that.

And so it is with a Spenser novel. In the wonderfully titled “Hundred-Dollar Baby,” April Kyle again calls on Spenser. You may remember the abused prostitute from “Ceremony” (1982) and the creative, if slightly desperate, manner in which Spenser saves her, placing her in the care of a kindly madam in an upscale bordello.

April now runs her own pleasure palace. When thugs try to horn in on the business, she pays a visit to Spenser’s office, looking for help. Spenser and Hawk have little trouble dealing with the immediate problem, only to learn that there are many other factors at work, and that everyone, including April, is lying about what’s really going on.

There are a few plot inconsistencies, but much as with the other great American detective series, Rex Stout’s Nero Wolfe tales, that’s easy to overlook for the joys of revisiting great old friends and some of the most consistently entertaining dialogue ever penned.

5. “Echo Park” (Little, Brown, 416 pages, $26.99) by Michael Connelly, the latest Harry Bosch detective novel, may be the best of them all. Still a member of the Open-Unsolved Unit of the LAPD, he is worried that he may have missed a clue that would have caught a killer years earlier, preventing him from committing nine more heinous murders. When a patrol car stops a van and the cops discover trash bags filled with body parts, the driver admits to the vicious crimes, including the unsolved murder of a young woman that has given Bosch nightmares for so long.

He’d love to close the case, and so would the higher-ups in the LAPD, but something is wrong and, against orders, Bosch picks away at it. The expert narrative combines clarity, suspense, sensitivity, and integrity to create what may be the best mystery of the year.

6. “Hollywood Station” (Little, Brown, 352 pages, $24.99) by Joseph Wambaugh is a spectacular novel about … Oops, I read the advance galleys and am not allowed to say anything until it’s officially published. Tune in again.