Alex Alterman is a "mystery worshipper" - hired by churches to experience their worship services as a member of the congregation and evaluate what works and what doesn't. Grass growing in the parking lot? Unkempt bathrooms? Bad sound systems? These may turn away people as much as the singing and the sermon. To whom much is given, much is required. But when Alex and his dedicated band of nitpicking zealots are hired to evaluate a Florida church and its prominent pastor, they are presented with a set of mysteries: Who hired them? And who hired their main competition? And why are they being shadowed by a couple of atheists running a dirt-dealing blog? Oil spills, dwarf spies, choir room surveillance, church league basketball cheats and parking lot security all combine in a splendid caper that stretches from Wall Street to the beachfront. As Alterman's group finds itself in the eye of the storm, the work takes on a new dimension as they untangle the reasons they believe in their work, and why they believe at all.