Mysteries and thrillers set in Africa that are as good as Kwei Quartey’s are remarkably rare. In colonial-era mysteries, plots centered almost entirely on intrigue among the white folks, while African characters were indistinct, showing up mainly as thieves or servants. With few exceptions, post-colonial mysteries weren’t much better at depicting the continent’s vast and varied humanity.

Recent years have been somewhat better. We’ve had Alexander McCall Smith’s No. 1 Ladies’ Detective Agency books, which many find charming, if borderline Hallmark-movie-like. And last year’s “American Spy,” by Lauren Wilkinson, was lauded for its incisive rendering of an American woman’s conflicted loyalties when she is enlisted by the CIA to spy on a revolutionary in Burkino Faso.

It’s Kwei Quartey, though, with his mysteries set in Ghana, who has been regularly bringing a part of the African continent authentically and strikingly to life. Quartey’s African American mother and Ghanaian father were university lecturers in Ghana, where he grew up. He graduated from Howard University’s College of Medicine and has been working as physician in California while also releasing, among other books, his Inspector Darko Dawson mysteries, which began with “Wife of the Gods” in 2009.

With “The Missing American,” Quartey has launched a new series with private investigator Emma Djan, and it’s a gem of a debut. This bright, appealing 26-year-old is the daughter of a homicide detective who aims to follow in her dad’s footsteps. After police department training, though, Djan gets stuck in a bureaucratic backwater, probably because she’s a woman. And when she shyly appears for an interview, hoping to be transferred to Homicide, the police commissioner tries to rape her. This unfailingly polite young lady — “Yes, please,” “No, please” — jabs the old reprobate in the eye and runs off. She is promptly fired for insulting her superior. With help from a relative, Djan finds work with a private detective agency run by an honest former cop, Yemo Sowah, and that’s where she comes into her own.

Both Sowah and the reader soon begin to appreciate and enjoy the way Djan learns to use her proper-young-lady deferential manner as an investigative tool. She’s a wonderful mix of decent values and applied canniness.

Djan’s first big case is the one in the book’s title. A middle-aged American named Gordon Tilson travels to Ghana to track down whoever swindled him out of $4,000 in an Internet scam. The widower, who married his Ghanaian sweetheart years earlier while in the Peace Corps, had been lured into a romance with a nonexistent woman, the creation of “sakawa boys,” Internet tricksters. But then Tilson disappears, and his son Derek hires the Sowah Agency to find his missing dad.

Internet fraud is big business in Ghana. Clever young university graduates with no employment prospects find easy money conning foreigners out of thousands of dollars online. Americans are especially gullible, falling for desperate-situation sob stories or opportunities for love or just affection. A sakawa-boy acquaintance of Djan’s insists that white foreigners exploited Africans for centuries, and now it’s the Africans’ turn.

Among Quartey’s colorful cast of characters is Kweku Ponsu, a corrupt traditional healer who provides the sakawa boys with magical powers for fooling more “mugus” and juicing up their earnings. They pay Kweku in cash, live chickens and an assortment of fetish items, like the hair of a white woman.

In addition to being suspenseful, “The Missing American” is wonderfully atmospheric, with people speaking mostly colloquial English, but also pidgin English and local dialects. Quartey has helpfully added a glossary, where we learn, for example, that a “grasscutter,” mentioned in passing in the narrative, is a “bush rat, the meat of which is used in soups and stews.”

One of Quartey’s most admirable characters is investigative journalist Sana Sana. He saves Djan when she’s about to be on the receiving end of some fatal “rough-rough” and is probably modeled after the real-life Ghanaian reporter the book is dedicated to, Ahmed Hussein-Suale. He was assassinated last year following his exposés of rigged soccer matches.

Sana survives an attempt on his life in “The Missing American,” and here’s hoping he shows up in future entries in this estimable series, along with the delightful Emma Djan.

Richard Lipez writes the Don Strachey PI series under the name Richard Stevenson.

THE MISSING AMERICAN

By Kwei Quartey

Soho Crime. 419 pp. $27.95