When Mike Roberts kicks over a homeless woman's cup of change, she whispers a cryptic warning:

"Mind the cracks . . ."

Now the Boston he knows and loves is unraveling around him. But his life is not the only thing at stake. His mother, a once acclaimed writer lost in the late stages of Alzheimer's, depends on him to have a home. And then there's her caretaker, Cassie, who might want something more from Mike than the friendship they've long shared.

As his city balances on a razor's edge, Mike will have to hunt down the daughter of the woman he wronged and uncover their terrible family secret . . . or be plunged into a world of crawling horrors and unspeakable hunger.

A world from which no one has ever returned.