Sir Timothy Edsel Vivor, Knight, Survivor, Time Traveler

You are a former knight trying to survive in a post-apocalyptic world by scavenging among the ruins of what is left. You have a backpack and a canteen. You haven't eaten in two days, you're desperately searching for food. You enter a rundown building and meet Mariana, the hobbitess, and subsequently fall deeply love. You learn that a time travel machine exists. You lose Mariana, tragically, despite your best efforts to save her. This loss drives you to retroactively save her and thus the world. You gain two allies, a theoretical physicist and a S.E.A.L. demolitions expert. "The event" that destroyed the world is preventable using time travel and knowledge of the exact time and date it occurred. Find out the date at one location. Find out the time at another. Find the time machine. Figure out how to power it. Use the TM to prevent "the event." Save Mariana. Save the world. Win the game.