What would happen if a time traveler lived in a world where time could not easily be changed and if it was changed, it might destroy everything but himself?
Pilot X comes from a race called the Alendans, who consider themselves the guardians of the timeline, and have the ability to move through space and time. They are locked in conflict with the Sensaurians, an organic hive mind that can send messages in thought throughout its own history, and the Progons, a machine race who can communicate backwards in time.
Pilot X is promoted to Ambassador and rings about a peace among the three races, but finds there is a secret Dimensional war happening in hidden parts of spacetime. He is brought in on a conspiracy to prevent the war from destroying the universe only to find that all his actions cemented the war and hid it further from general knowledge.
He is faced in the end with a choice to erase all three peoples from existence, including the Alendans, or let the universe be destroyed. Saving the universe leaves him as the only survivor of the three time-traveling races, and the only person who knows the war ever existed.