"…in this business, at some point, everyone dies." Carl Santos CIA Station Chief, Istanbul Twin sisters Courtney and Whitney spent their entire adult lives traveling an inherently dangerous path - sometimes together, sometimes apart. It's a path that inexorably leads to a destiny that only they - together - can fulfill. Over the years, they've made friends, and enemies - sometimes both in the same person. Even those they work against, respect their abilities. They now find themselves forced to work with what the world believes is their biggest adversary - the SVR - and its Director. What the world - and those in power in both countries - aren't aware of, is that over the years, Courtney Whitman and Andrei Gryzlov have become as close as friends, as they are diligent adversaries. This small detail will eventually prove extremely beneficial for the Russian government. A program - one that directly involved two of the twin's closest associates - was never terminated as was reported. In fact, not only was it seen through to completion, but the subjects are now being gathered to complete a mission - but it's not the mission they were created for. Older, and perhaps a split second slower than they were in their youth, the sisters find themselves caught up in the bizarre plan that Akilina Nikolsky believes will propel her into the Presidential Palace in Moscow, drawn into the melee by an old friend and adversary - Leonid Tarasov. Having discovered the truth about his - and many other's - origins, he deceptively recruits the sisters who, once they understand what is at stake, readily join him on his quest to thwart the insanely diabolical plans of Akilina Nikolsky, and the deranged scientist that is helping her. In the end... the price of success will be far higher than any of them could have ever imagined. The Final Equation is the last chapter in the lives of Courtney and Whitney Bergstrom, and all those who have joined them over the years, on the extraordinary path that leads to their ultimate destiny.