The House of Unexpected Sisters

This novel in Alexander McCall Smith's No. 1 Ladies' Detective Agency series is set in Gaborone, Botswana. Precious Ramotswe, known by the Setswana honorific Mma, runs a small detective agency alongside her co-director, Mma Grace Makutsi, a proud graduate of the Botswana Secretarial College. Mma Ramotswe's husband, Mr J. L. B. Matekoni, operates Tlokweng Road Speedy Motors next door, where his perpetual apprentice, Charlie, works on cars.

The story begins when Mr Polopetsi, a part-time chemistry teacher who volunteers at the agency, brings a case to their attention. A widow named Charity Mompoloki, who has young twin boys, has been fired from her job at The Office Place, an office furniture store, after allegedly being rude to an important customer. Charity denies the accusation, and despite there being no prospect of payment, Mma Ramotswe agrees to investigate.

Mma Ramotswe, Mma Makutsi, and Mr Polopetsi visit Charity at her modest home. She maintains her innocence, and Mr Polopetsi suggests the employer may have fabricated the complaint. When asked about enemies, Charity names Violet Sephotho, who has held a grudge since Charity caught her copying an essay at the Botswana Secretarial College. Mma Makutsi recognizes Charity as a fellow alumna and the two embrace warmly, but Mma Ramotswe privately worries that this loyalty may cloud Mma Makutsi's judgement.

Seeking objectivity, Mma Ramotswe drives to her home village of Mochudi and visits Charity's mother, Mma Lentswe. The elderly retired teacher reveals that her daughter is headstrong and prone to outbursts of rudeness, and she believes Charity probably was rude, though she considers the punishment harsh. During the visit, Mma Lentswe shows Mma Ramotswe a newspaper clipping featuring a nurse named Mingie Ramotswe, age 43, from Lobatse. The woman's face strikingly resembles Mma Ramotswe's own, puzzling her because she thought she knew everyone who shared her uncommon surname.

Mma Ramotswe consults her close friend Mma Potokwani, the formidable matron of the local Orphan Farm, who delivers unsettling news: Mma Ramotswe's abusive first husband, Note Mokoti, has been spotted in Gaborone. Though Mma Ramotswe long ago forgave Note and told him she never wanted to see him again, the news fills her with dread. On the Charity case, Mma Potokwani suggests letting Mma Makutsi and Mr Polopetsi pursue their own line of enquiry while Mma Ramotswe follows hers. On the Mingie matter, she advises finding out what kind of person Mingie is before making contact.

Mma Ramotswe assigns Mma Makutsi as "Principal Investigating Officer" on the Charity case and begins investigating Mingie herself. Through Sister Banjule, a hospice nurse, and Stephen, a garrulous hospital porter in Lobatse, she learns that Mingie is an operating theatre nurse described only as "different." A neighbor gives a heartfelt endorsement, calling Mingie one of the kindest people she knows. Reassured, Mma Ramotswe leaves a note under Mingie's door inviting her to the agency.

At The Office Place, Mma Makutsi and Mr Polopetsi interview employees. Charlie, who drives them, theorizes that the store's boss, Mr Gopolang, fired Charity to give her job to a girlfriend. Flora Mbeli, a long-serving colleague, confirms Charity was indeed rude to the customer on one occasion but considers the punishment disproportionate. Mr Polopetsi separately learns from another employee, Gloria, that Gopolang intends to expand into house furniture, directly competing with the Double Comfort Furniture Store, a business owned by Mma Makutsi's husband, Phuti Radiphuti. Gopolang plans to buy out Phuti's supplier and sell at a loss to drive Phuti out of business. Mr Polopetsi shares this privately with Mma Ramotswe. Mma Makutsi then organizes a surveillance of Gopolang and follows his car to a house where he picks up a woman she identifies as Violet Sephotho, which she takes as proof that Gopolang fired Charity to install Violet.

Mingie arrives at the agency, and Mma Ramotswe is stunned by how alike they look. The two women embrace and weep. Walking together behind the office, Mingie explains she was born near Mochudi and raised in South Africa after her mother left Botswana. She never knew her father, whom her mother described as "not a good man." When Mma Ramotswe asks his name, Mingie answers: Obed. Based on the newspaper's reported age, Mma Ramotswe calculates that Mingie was born while her own mother was still alive, meaning her beloved father fathered another child during his marriage. That evening, she tells Mr J. L. B. Matekoni her heart is broken and calls her father a hypocrite. The discovery shatters her idealized image of Obed Ramotswe as the embodiment of old Botswana morality.

Mma Ramotswe rejects the idea of using Gopolang's affair as leverage, considering it morally equivalent to blackmail. On Mr J. L. B. Matekoni's advice, she visits Gopolang's wife directly. Mma Gopolang, an extraordinarily forceful woman, laughs and says she already knows her husband strays. She then reveals that she herself engineered Charity's firing. Violet Sephotho, who is actually Gopolang's cousin rather than his mistress, told Mma Gopolang that Charity was the woman having the affair with her husband. Mma Gopolang arranged for a friend to lodge a false complaint against Charity. Mma Ramotswe sees the full picture: Violet manipulated her cousin's wife to eliminate Charity over an old college grudge. The actual complaint was entirely fabricated. Mma Gopolang readily agrees to have Charity reinstated.

Still grieving over her father, Mma Ramotswe drives to the graveyard in Mochudi where her parents are buried. At Obed's grave, she wrestles with her anguish and forces herself to forgive him, though doing so feels like saying a final goodbye. She then accepts Mingie's lunch invitation in Lobatse, where she meets Keeya, a mathematics teacher who shares Mingie's home. On the veranda, Mingie casually mentions that the newspaper got the ages wrong: She is younger than 43. Mma Ramotswe recalculates and realizes with overwhelming relief that Mingie was born after her mother died. Obed was free. There was no betrayal. She breaks down sobbing with joy, understanding that her father did not leave Botswana when Mingie's mother emigrated because he had Precious to care for and was already ill from years in the mines. When Mingie notes that she and Keeya have lived happily together for years, Mma Ramotswe places her hand over Keeya's and says she now has two sisters.

Back in Gaborone, Mma Gopolang visits the agency to confirm Charity's reinstatement. She reveals that Violet had been interfering extensively in the business, including orchestrating the scheme to undercut Phuti's store, and she has torn up the deal. When Mma Gopolang asks the agency to identify her husband's actual girlfriend for revenge, Mma Ramotswe firmly declines, insisting on forgiveness.

Finally, Mma Potokwani tells Mma Ramotswe that Note Mokoti is in Gaborone to arrange his wedding. He sent a message through Mma Potokwani: He has changed, he is sorry, and he wants forgiveness. Mma Ramotswe decides to send him a wedding present, giving him the blessing he seeks. Driving home in the evening light, she stops the van under a tree and listens to the sound of cattle bells, her father's favorite sound, thinking of everyone she loves and feeling a love "greater than the Kalahari itself, and wider than the sky above."