Marcus Sakey so closely ties his second novel to the ambience and atmosphere of Chicago that readers will be flipping through maps trying to find the fictional locales in “At the City’s Edge” (Minotaur/St. Martin’s Press, $24.95).

The South Side Chicago neighborhood of Crenwood doesn’t exist, but Sakey’s keen tale of greed and politics makes the reader feel quite at home. As he did in last year’s excellent debut, “The Blade Itself,” Sakey wraps his tension-laden story around a man rebuilding his life. “At the City’s Edge,” employs many of the mystery genre’s conventions but Sakey’s skills make his novel fresh and original.

Iraq veteran Jason Palmer has come home riddled with guilt over his war experiences. He finds a neighborhood being squeezed by violent gangs and corrupt politicians. Crenwood is “at the city’s edge.” “We’re covered with tumors, but nobody’s looking,” says a community leader.

His brother, Michael, has turned community activist, working with the police to clean up the neighborhood that the brothers grew up in. Then Michael is murdered and his 8-year-old son is targeted. Jason finds that his feelings mean little when his neighborhood is under siege and his nephew needs someone responsible in his life.

Michael wasn’t the only one trying to make a difference in Crenwood. Elena Cruz, the first woman to be assigned to the police force’s elite gang intelligence unit, saw working with Michael as a way to prove herself to her superiors.

The two team up and discover that multiple layers of corruption have made their streets mean. As one character says, “this is Chicago. Everything is political.” Sakey never lets “At the City’s Edge” rest, creating an emotional link between war-torn nations and inner-city woes that gives energy and texture to the plot.

Sakey, whose previous writing consisted of advertising copy, knows how to create realistic suspense and action that puts him in league with authors such as George Pelecanos and T. Jefferson Parker.