The CIA forces twelve-year-old Charlotte "Charlie" Thorne, a rebellious genius, to use her code-breaking skills on an epic global chase to locate Einstein's last equation before dangerous agents discover it and unlock the solution to harnessing energy.

Decades ago, Albert Einstein devised an equation that could benefit all life on earth, or destroy it. Fearing what would happen if the equation fell into the wrong hands, he hid it. But now, a diabolical group known as the Furies are closing in on its location. In desperation, a team of CIA agents drags Charlie Thorne into the hunt, needing her brilliance to find it first, even though this means placing her life in grave danger. In a breakneck adventure that spans the globe, Charlie must crack a complex code created by Einstein himself, struggle to survive in a world where no one can be trusted, and fight to keep the last equation safe once and for all.