With the exception of a brief sojourn in Belgium and flashbacks to a childhood in Nigeria, Teju Cole's brilliant debut novel, "Open City," was set firmly and squarely in New York City. His protagonist, a Nigerian immigrant named Julius, spent the novel pounding its streets, absorbing its color and letting its detail trigger reflections, opinions and memories.

Cole's second novel, "Every Day Is for the Thief" (Random House, 162 pages, $23), is cut from similar cloth. The narrative is made up again of wandering feet and thoughts, only this time the narrator has left New York to re-explore Lagos, the hometown he left 15 years ago. He is nameless but could well be Julius — his past tallies, he is a writer and student of psychiatry, and his mind roams and records in the same omnivorous and mesmerizing way. Whoever he is, it is a pleasure to be in his company.

No sooner has his plane touched down in Lagos than he is accosted by an official scrounging for dollars. Shortly afterward his aunt greets him and tells him that despite the years, he hasn't changed. This may or may not be true; what is clear is that the more he rediscovers his native city, the greater his understanding of how it has changed. The biggest difference is the way money is acquired. The "informal economy" is still woefully prevalent, but what was then discreet is now brazen. He spots cops hitting drivers with trumped-up charges under a billboard that reads, "Corruption Is Illegal: Do Not Give or Accept Bribes." Gangs of feral boys play the same game as the airport official, but with guns, the money they demand "less a tip than a ransom." Enterprising teenagers blithely perpetrate e-mail fraud from Internet cafés.

Cole's narrator walks and muses while taking in his surroundings with both weary familiarity and a foreigner's fresh and frequently culture-shocked outlook. He catalogs outbreaks of casual violence, braves free-for-all traffic on danfo buses and okada motorbikes, and finds a music shop that deals only in pirated copies. Certain episodes are devoid of incident — staring at a girl, catching up with an old friend, sitting through a power outage — but impress with their cool, spare observation. Lagos emerges as a seething, hectic hub that at the same time has "the general air of surrender."

"Every Day Is for the Thief" is actually Cole's first novel, published in Nigeria in 2007. This may explain why it doesn't advance on "Open City." Meditations on history, religion and slavery lack the depth of its predecessor, and some sections feel journalistic rather than that previous Sebaldian blend of fact and fiction. That said, Cole's prose is as intoxicating as before, his narrator's curiosity infectious and his depiction of Lagos, a city where "life hangs out," stunning.

Malcolm Forbes has written for the Times Literary Supplement, the Economist and the Daily Beast. Born in Edinburgh, he lives in Berlin.