On February 1, misanthropic l’Cie Paddra Ballad-Caius of the Farseer tribe, protects Yeul. Forced to witness the Yeul die with each vision, a grumpy Caius goes to sleep.
Caius wakes up to find that he is reliving February 2. The day plays out exactly as before. Caius commands the powers of chaos to warp the timeline with no fear of long-term consequences. However, his attempts to get closer to Yeul, to whom he has become the sworn protector, repeatedly fail.
Eventually, Caius becomes depressed and tries more and more drastically to end the time loop; he makes the timeline unstable by manifesting time paradoxes in an effort to change the fate of Yeul. Caius eventually pursues Noel and Serah in the form of Chaos Bahamut and engages them in an aerial dogfight.
Being unable to die as long as Etro’s heart beats inside his chest, Caius finds that nothing’s changed. Further attempts at suicide also fail to break the time loop. He continues to wake at six o’clock with the clock radio on his nightstand playing “I Got You Babe” by Sonny & Cher.
When Caius explains the situation to Yeul, she spends the day with him. However, he awakens again, alone, still in the time loop. Eventually, Caius endeavors to improve himself. He begins to use his by-now vast knowledge of the timeline to
- defeat Noel,
- fight Lightning,
- kill Serah,
- play the piano.
Eventually, Caius is able to
befriend screw over almost everyone he meets during the day, using his experiences to save lives create paradoxes, help townspeople create more paradoxes, and ultimately to save Yeul create even more paradoxes, without having to resort to manipulation as on previous days.
Caius eventually seizes Noel’s blade and forces it through his chest to destroy the Heart of Chaos. He then collapses and fades away. He wakes the next morning on a new day; it is now February 3, exactly 500 years in the future.