Zoe Tampsin is resourceful, smart, and special forces-trained, but she has an impossible mission. She must protect scientist, Gavin Shawlens, from assassination by the CIA, and discover a secret trapped in Gavin's mind that the CIA want destroyed. As the pressure to find Shawlens escalates, the CIA send Zoe's former mentor to track her down, and her fate seems sealed when he surrounds Zoe and Gavin with a ring of steel. With each hour that passes, the ring is tightened, and the window for discovering Gavin's secret will shut. Zoe is faced with a decision that goes against all her survival instincts. If she's wrong, they die. If she's right, she will discover the secret, and become the next target for assassination.