Lisette Lecat doesn’t simply portray the characters in McCall Smith’s series about Botswana’s No 1 Ladies’ Detective Agency and the Speedy Motors car repair service that improbably share a building in the nation’s capitol city: she is Mma Ramotswe, that robust, throaty and ever-so-kind detective. Lecat is also Ramotswe’s husband, Mr. J.L.B. Matekoni, whose rumbling pronouncements sound as if they originate in one of the beaten-down Mercedes he tenderly mends. Ramotswe’s assistant, Mma Makutsi, makes her caustic comments in a pencil-sharp voice. Even Makutsi’s shoes, which offer advice to their wearer from time to time, have a down-to-earth tone to them. Each volume of this series offers Lecat a few new characters to inhabit. She does especially well with a rude, shrill client who thinks her husband is cheating on her. Even though the series is becoming a bit repetitious, Lecat brings so much love and skill to her rendition of the characters that this will charm both old fans and newcomers alike. Simultaneous release with the Pantheon hardcover (Reviews, Feb. 22). (May)