"Tango Down" (Permanent Press), by Chris Knopf

Sam Acquillo is plagued with problems in "Tango Down," the latest in Chris Knopf's entertaining and well-written series about a former professional boxer turned Long Island cabinetmaker and amateur private detective.

Amanda, Sam's lover, has fallen critically ill. Victor Bolling, the owner of a house that Sam is working on, has been bludgeoned at the work site. And Ernesto Mazzotti, a carpenter that Sam likes and respects, has been charged with the murder, bringing out the worst in their neighbors' anti-immigrant bias.

Everything gets much worse when Sam's lawyer-friend Jackie Swaitkowski agrees to represent Mazzotti and hires Sam to help with the defense.

In Knopf's first seven Acquillo novels, Sam has taken on and bested thieves, killers, drug dealers, crooked businessmen and corrupt cops in his little corner of western Long Island, but "Tango Down" finds him in over his head. It turns out that neither Bolling nor Mazzotti are what they seemed.

Soon, their work for the defense entangles Sam and Jackie in an unfamiliar world of FBI agents, spies, South American revolutionaries and covert intelligence operations.

"It wasn't just a world of shadows, it was a world without light," Sam says in a dark moment when it seemed that he and Jackie might never uncover the truth — and might not even come out alive. "I thought I knew, more or less, how the world worked. Turns out I was mostly wrong."

But even then, just 40 pages from the book's stunning conclusion, fans of the series will have faith that Sam's intelligence and sheer stubbornness with finally achieve at least some measure of justice.