The Minor Adjustment Beauty Salon

Some detectives were made to work alone: Sam Spade, Philip Marlowe and Clovis Anderson, author of "The Principles of Private Detection.”

Precious Ramotswe, however, finds herself at a loss after she is bereft of her Watson in “The Minor Adjustment Beauty Salon,” the 14th entry in Alexander McCall Smith’s beloved No. 1 Ladies’ Detective Agency series.

After refusing for months to discuss her rapidly expanding waistline, Grace Makutsi Radiphuti finally admits she’s pregnant – just days before giving birth to young Itumelang Clovis Radiphuti.

While Precious thought she would enjoy the respite, she desperately misses her bossy associate detective – even Grace’s habit of talking to her shoes. And without a partner to bounce ideas off, her cases are suffering as well. Lawyer Sheba Kutso has hired the agency to investigate a young man calling himself Liso Molapo, suspecting he isn’t the real nephew to whom her late client left much of his estate. And someone is spreading malicious rumors about Mma Soleti, the owner of the titular beauty salon, destroying her business.

Grace, meanwhile, is adjusting to new motherhood and trying to cope with her husband’s poisonous aunt, who has moved in to “help” with the baby. And in the sweetest plotline, Mr. J.L.B. Matekoni, who wants to help out more at home, signs up for a course, “How to Be a Modern Husband (Level  1).” (Many potatoes valiantly give their lives in his hilarious show of devotion.)

“The Minor Adjustment Beauty Salon” is a particularly endearing entry in the long-running series, which has lost none of its gentleness or its love for Botswana, of which McCall Smith clearly has fond memories. The prolific author (at this point, critics are contractually obliged to call McCall Smith “prolific” at least once in every review) takes his time with the plot, sprinkling in plenty of musings about what makes a good detective and what really constitutes “profit.”

“Could you say that your business had expanded if it had gone from owning one teapot to two?” Precious wonders after reading a business article. While the agency has never turned a profit, it also hasn’t posted a loss recently, thanks to what a bookkeeper dubs “optimistic accounting.”

When a surgeon disparagingly comments, “Even my grandmother could be a private detective,” Precious considers the insult thoughtfully: “A grandmother would make a very good detective, she thought: grandmothers had seen a lot of human nature and could use that knowledge well.”

In a true sign of grace, even Charlie, the least prepossessing of Matekoni’s apprentices, shows some late-breaking maturity. Phuti Radiphuti’s aunt, however, may be beyond even the capacious reserves of Precious’s patience, although the optimistic detective is determined to give it a shot.

“It was always worth trying: there were few people who were so unpleasant that you could not get through to them with courtesy or praise,” she thinks.

Failing that, as another character discovers, sometimes a dead cobra comes in handy.

In a series that takes kindness as a watchword, McCall Smith is unlikely to permanently break up his winning duo. He leaves his main characters, mysteries sorted, bathed in a red sunset over Botswana.

“The glow left by the sun is like a good act done,” Precious thinks, “or like love, which left the same warm signature behind.”

Yvonne Zipp is the Monitor fiction critic.