The riveting sequel to Simple Simon (made into the Bruce Willis movie Mercury Rising) is finally here.

When he was a boy, Simon Lynch broke a National Security Agency super code. Now, 20 years and a half trillion dollars later, the government is on the precipice of unlocking the secrets hidden in his damaged mind.

For two decades, they've poured money and scientists into an effort to breach the autism which has kept Simon Lynch all but inaccessible to those who most want to exploit his brilliance. But as that covert project is about to bear fruit, an outside entity has zeroed in on the now 36-year-old man, seeking him for their own, more destructive purposes.

As before, the first line of defense against those with designs on the savant is now retired FBI Special Agent Art Jefferson. But also drawn into the maelstrom which develops around Simon is FBI Special Agent Emily LaGrange. Barely surviving a grueling two-year undercover assignment, she's now assigned as liaison to the NSA project that studies Simon in a remote, secure facility.

Security, though, is never absolute, and those who want Simon will go to any lengths to have him, forcing Emily LaGrange to confront both them, and her own demons, to save the innocent man from certain death - or a fate even worse than that.