In literature, it is rare to find a perfect and clearly delineated accession, like the monarchs of England or the popes of the Roman Catholic Church. Time periods and styles overlap so that it is generally impossible to see the handing off of the baton from one monumental figure to the next. But there is one subgenre of the mystery novel in which there can be no mistaking the landmark figures: the hardboiled private eye story.

The first author to write serious literature within the confines of the private eye novel was Dashiell Hammett, who examined social issues, questions of friendship and loyalty, and even elements of existentialism. He nearly invented the form and certainly refined it, beginning in the early 1920s and essentially finishing in 1934, when his fifth and last novel, “The Thin Man,” was published.

Raymond Chandler followed immediately, selling stories to the pulps in the mid-1930s and publishing his first novel, “The Big Sleep,” in 1939, and his last of consequence, “The Long Goodbye,” in 1953 (I don’t count “Playback,” his sadly inferior work published in 1958). In his six major novels, he raised the literary style of the genre to such dizzying heights that even the stuffiest critics were forced to acknowledge it.

Trotting along right behind the great Chandler came Ross Macdonald and his Lew Archer series. The early books (published in the 1950s) were, as Macdonald admitted, pastiches of Chandler’s work. He found his own voice in 1959 with “The Galton Case.” Macdonald’s explorations of family relationships and their psychological impact were soon read as devotedly for their literary mastery and sensitivity as they were for their excellence as detective stories. His last novel, “The Blue Hammer,” was published in 1976.

And there, waiting to assume the mantle of greatness, was Robert B. Parker, whose first Spenser novel, “The Godwulf Manuscript,” was published in 1973. By far the most prolific of those in the small pantheon, his 33rd novel in the series, “School Days” (Putnam, $24.95, 295 pages), has just been published.

None of this is to say that there have not been other great writers of hardboiled fiction. Paul Cain’s “Fast One” stands as a towering achievement of violent action, and Mickey Spillane has no peer when it comes to clarity of prose and the moral vision of his series hero – Mike Hammer, though he had none of the literary aspirations of Hammett, Chandler, Macdonald, and Parker. James Crumley’s “The Last Good Kiss” remains, in my opinion, the single greatest private eye novel ever written, though he has written too seldom and too erratically to take a place in the Hall of Fame.

“School Days” is a typical Spenser novel in many ways – it has the same crisp dialogue, sharp wit, bravery, and humanity that are the hallmark of these superb adventures. It is different, however. Susan Silverman is away at a conference, and so her only appearances are in brief telephone conversations and a happy reunion with our hero in the last chapter. This highly intelligent character is based on Dr. Parker’s wife Joan, to whom almost every one of his books has been dedicated. Her caustic and sarcastic banter to the contrary, it is impossible not to realize that they are the love of each other’s life. (This goes for both couples: Spenser and Susan as well as Bob and Joan Parker.)

Pearl, a German shorthaired pointer (also based on a real-life character, the Parkers’ Pearl the Wonder Dog) makes numerous appearances, but one of crime fiction’s most memorable characters, Hawk, is absent. Even conceding that he wasn’t needed in “School Days,” it’s as disconcerting to read a Spenser novel without Hawk as it would be to read a Sherlock Holmes story without Dr. Watson.

The elements that drive the novel are pulled from the headlines of the past several years. The first involves teenagers going to school with serious weaponry and opening fire, killing students, teachers, and anyone who happens to be in their line of fire. Alas, I can’t tell you the other one, as it provides the stunning denouement to this perfectly plotted thriller.

“School Days” opens with an elderly lady hiring Spenser to prove her grandson innocent of taking part in the school massacre. It will be an uphill battle, as the other boy has fingered him. Also weighing against him is the fact that he confessed. When he declines to cooperate, sniggers and smirks when asked questions (Spenser says, “he deserved to do some time for the aggravated smirking”), and refuses to offer any explanation for the wanton violence, it appears to be a lost cause. Everyone wants the case to be closed quickly and the boys shipped off to jail. The police, lawyers, other students, teachers, principal, guidance counselor – even the parents – want to close the episode and move on with their lives.

But Spenser is stubborn. You already know that if you’re a fan of this series-and if somehow you’re not, you need to see someone and get help. Like Pearl on a soup bone, Spenser doggedly (sorry, I couldn’t help myself) stays on the case, poking here, scratching there. “Being a seasoned investigator,” he says, “I have found that when there’s stuff you don’t know in a case, it’s best to find it out.” He finally uncovers the clue that will provide the solution to the case. It’s not a fairy tale, with everyone living happily ever after, but it’s fair. As in life, that’s the best one can hope for.

Mr. Penzler is the proprietor of the Mysterious Bookshop in Manhattan and the series editor of the annual “Best American Mystery Stories.” He can be reached atopenzler@nysun.com.