03E08 - Twilight

Enterprise is hit with a rather intense anomaly. Refusing to leave an injured T'Pol behind, Archer is struck by the anomaly, leaving his brain infected with parasites, preventing him from making any new memories. Fast-forward 12 years. T'Pol has been caring for Archer since his affliction. As she does every day, T'Pol catches Archer up on the past 12 years, knowing he will forget everything within hours. She was in command of Enterprise after his injury, that the parasites live outside normal space-time and usual remedies never worked, that the Xindi were successful, and managed to destroy Earth and kill all but 6,000 humans. But today is special; Dr. Phlox is ready to give Archer the treatment he has been developing for ten years, which must be performed on Enterprise.