Series numeration from Fantastic Fiction.

"When Mitch Rapp captures ISIS's top technology expert, he reveals that he was on his way to meet a man who claims to have the ability to bring down America's power grid. Rapp is determined to eliminate this shadowy figure, but the CIA's trap fails. The Agency is still trying to determine what went wrong when ISIS operatives help this cyberterrorist do what he said he could--plunge the country into darkness. With no concept of how this unprecedented act was accomplished, the task of getting the power back on could take months. Perhaps even years."-- from Publisher.