The FBI has found Dr. Jeff Jacobs' time travel device in California's Sierra Nevadas. Only, he has no idea how it got there. Because of his work in time travel research, though, Jeff is introduced to a mysterious woman claiming to be a time traveler originating in another reality. Her story is compelling: she'd gone back to 1983 to assassinate a particularly dangerous officer in the Soviet military, a mission that had ultimately changed the world as she knew it. Now, based on time travel theories that have yet to be tested - and may or may not be accurate - Jeff is shanghaied into helping to make permanent the history-changing events that had taken place over thirty years before. Jeff is willing to help the cause, but only to regain control of his research and understand how his device ended up in California. With a gun to his head more often than not, Jeff comes face-to-face with the dangers of changing history and a humbling understanding that his reality just might not be the original one.