Toby Ball’s gripping third novel, “Invisible Streets,” features not one but three interlocking investigations. Set in an unnamed city in the 1960’s, the main mystery kicks off when a large supply of demolition explosives is stolen and the three security guards on duty go missing.

The theft threatens the controversial New City Project, a plan to build highways that link the center of the city with the suburbs. The project is held together with bribes and double-dealing. The big question with the explosives is why they haven’t been re-sold back to the New City Project.

Detective Torsten Grip searches for the missing guards to find what happened to the explosives. Legendary reporter Frank Frings searches for his friend’s missing grandson, only to find his quest intersecting with the missing explosives. And Phil Doman, who takes care of the mayor’s dirty work overseeing the New City Project, tracks the progress of anything that might affect the project – such as missing explosives.

As they ask questions, the three men gradually unearth some big and troubling secrets. Through their questions, Ball gradually reveals the real politics that run the city.

The fourth main character is the city itself, anonymous but recognizably American. Sprawling, gritty, corrupt, nearly ungovernable, the city needs firm hands to guide it.

“Take a look at the size of this place,” says one character. “They say the cop’s job is to protect, but it’s to control, at least here.” The city pulses with danger. Ball makes you feel the grime and dirt as the men crisscross the city looking for answers.

He writes in short, rhythmic chapters that keep the densely plotted story moving. Beyond the tense storytelling lurk bigger questions. Is the city structured for people or for automobiles? What produces the feelings of alienation in the citizenry? What are acceptable uses of power in trying to govern such a metropolis? Fans of thrillers that wrestle with larger questions will be enthralled.