In Calder Bay, two researchers discover an ancient lighthouse hidden beneath the sea, powered by an advanced artificial intelligence built centuries ago to monitor oceans and guide humanity through catastrophic floods. As they awaken the system, they realize it holds the power to reconnect a global network of lighthouses, providing evacuation guidance and long-term survival strategies for billions of people. Tasked with controlling the system, they must navigate its secrets, protect it from misuse, and decide how to reveal its existence to a world unprepared for the truth.