Following her triumphant return from the past and the shock of finding her best friend Mason newly ensconced at Gray Wolf, Natasha is looking forward to her new assignment in Renaissance Italy where she'll be accompanied by her boyfriend Braxton, only to learn at the very last minute that Braxton has been reassigned and the infuriating Killian will be joining her instead.

Natasha has no choice but to go along with the new plan, only to discover Killian's task is nothing like hers. He's not there to procure rare pieces of art, but rather to work as Arthur's assassin.

As Natasha begins putting the pieces together, she soon learns the startling truth behind Arthur's ultimate invention: a quantum computer that allows him to see the long-term effects of lives lived and lives taken. A program that will ultimately allow him to move toward his ultimate goal of repainting the past like a canvas-for he who controls time, controls the world.