The literary world lost two immortals earlier this month. Ira Levin, who died of a heart attack November 12 at the age of 78, was viewed with affection by all who knew him, while the degree of his fame remained somewhat below the level of his accomplishments. Norman Mailer, on the other hand, received, shall we say, mixed reviews, while his fame dramatically surpassed his achievements as a writer.

The gentle, somewhat reclusive Levin produced his first mystery novel, a masterpiece that succeeded in flummoxing even the most astute reader, when he was 23. “A Kiss Before Dying” went on to win the Edgar Allan Poe Award as the Best First Mystery of 1953. It remains one of my dozen favorite mysteries of all time, and I beseech you not to hold the two execrable filmed versions against it. He was more fortunate in the motion pictures made from his horror classic, “Rosemary’s Baby,” his Nazi thriller, “The Boys From Brazil,” and his fantasy, “The Stepford Wives” (the first film adaptation being a good one, while I hated the second as much as a turkey hates a cookbook). As proof that no writer is immune from a bad day, Levin also wrote “Sliver.”

His comic thriller, “Deathtrap,” may have been the most successful mystery play ever to run on Broadway. His first foray to Broadway was an adaptation of “No Time for Sergeants,” which ran for nearly 800 performances and launched the career of Andy Griffith. Levin also wrote the lyrics for the giant Barbra Streisand hit, “He Touched Me.”

In 1953, he was named a Grand Master for lifetime achievement by the Mystery Writers of America, although he had written only seven novels in a career that spanned more than a half-century.

Norman Mailer got the headlines, however, as celebrities do, when he died November 10 at the age of 84. He had numerous connections to the world of crime, both literary and actual. His private-eye novel, “Tough Guys Don’t Dance,” was so awful that generous and bamboozled critics thought it was a hilarious satire. Had the lowest-paid pulp writer in the cheapest of the 1930s pulps written a line like “Your knife is in my dog,” he never would have worked again, yet Mailer became a two-time winner of the National Book Award. To exacerbate the horror, he then filmed it. One of the kinder reviews, in the Chicago Reader, described the movie as “ponderous and absurd, like the novel.”

His big CIA novel, “Harlot’s Ghost,” has been justly forgotten, while superior but lesser-known authors of espionage fiction, such as Charles McCarry and Robert Littell, have had their work reprinted years after initial publication.

A personal anecdote, in the interest of fairness: When planning this book, he came to my bookshop and asked me to recommend the five best CIA novels ever written. (If you’re interested, they were Mr. McCarry’s “The Tears of Autumn” and “The Secret Lovers”; Brian Garfield’s “Hopscotch”; James Grady’s “Six Days of the Condor, ” and Ross Thomas’s “The Cold War Swap.”) He was the essence of charm and graciousness.

Less charming was the multiple stabbing of his second wife, Adele, which nearly killed her. But his basest action was his role in getting the convicted murderer and habitual criminal Jack Abbott released from prison.

Abbott once bragged that he had had more charges filed against him while in prison than any other convict. When he learned that Mailer was writing a book about the imminent execution of Gary Gilmore, he began to write long letters to the famous author, who saw so much talent in their prose that he spearheaded an effort to have him paroled. This was in the era of the far left’s experiments with what Tom Wolfe named “radical chic.” Although the parole board had its doubts, Mailer and his allies prevailed, stating that “culture is worth a little risk.” Abbott’s letters were collected and published by Random House, which also published his sponsor. Six weeks after his release, Abbott got into a petty argument with a waiter and stabbed him in the chest, killing him almost instantly. The very next morning, the New York Times ran a favorable review of “In the Belly of the Beast,” adding that “we must be grateful to (Mailer) for helping to get Abbott out on parole.”

Ira Levin was often a wonderful writer, and I will mourn his passing. Norman Mailer was often a wonderful writer.

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 at ottopenzler@mysteriousbookshop.com.