The President and Vice President were killed in a terrorist attack. Now it seems that a secret branch of the government has in their possession technology from the alien landing at Roswell, and they were able to use it to create a time machine that can send someone back in time seven days. And they would like to send someone back before this happened and tell what's going to happen before it does so they can prevent it.

Parker is assigned as the "chrononaut" for Backstep. While memorizing all the mission details, Parker discovers via TV that his son has been killed by poison gas during the attack on DC. Finally, the backstep is authorized.

Recalled from a survival exercise, Parker has to go back to prevent the release of a virus that will devastate the world's population.