Picking up where 'The Inner Circle' left off, Meltzer posits more conspiracy deep inside the US Government, this time a long-standing secret society in which all four presidential assassins belonged. When murders that replicate these four historical assassinations begin, no one is safe. The society is not the only mystery that must be solved, but also how these four men, with no apparent connection, communicated over the span of 100 years. Just as things seem to be leading to a culmination of the story, the current POTUS in the crosshairs, Meltzer drops the proverbial floor from under the reader.