In literary circles, insofar as such still exist, for reasons I have never been able to grasp, I’ve often encountered disdain for “series” fiction of the kind particularly common in crime fiction and, to a lesser degree, science fiction. Of course, if you write a lot of books — one a year, perhaps, or thereabouts — over a stretch of time, featuring mostly the same principal character(s), often in the same setting, it’s easy to fall into bad habits. But that’s also true for writers of many different varieties. Several high-profile names spring immediately to mind. Between the late 1940s and the mid-1970s, one of the best American writers of the second half of the 20th century, Ross Macdonald, wrote 18 novels narrated by private eye Lew Archer. All of them are good, repaying a reader’s attention even on second, third, or fifth readings. P.D. James’s hand did not lose its cunning between 1962, when she introduced her Scotland Yard detective, Adam Dalgliesh, and 2008, when the last of her 14 Dalgliesh novels was published.

Sometimes, I’ll acknowledge, I grow weary after following a series for years. When Alexander McCall Smith began writing about the No. 1 Ladies’ Detective Agency, my wife, Wendy, and I were both fans — we enjoyed the audiobook versions as well. Alas, around the 10th novel in the sequence, we dropped out. But plenty of readers have stayed for the long haul — the 25th book in the series, The Great Hippopotamus Hotel, is coming in October.