After Enterprise is assaulted by severe spatial distortions, Archer loses the ability to form new, long-term memories, causing him to wake up each morning unaware that any time has passed since the day he was afflicted. Despite the crew's best efforts to keep him involved in decisions, it becomes clear over time that they can't continue to function in this manner, leading T'Pol to become his caretaker and Trip to take command of the ship.
