A light in the sky shines suddenly over Priora, giving Isaac and his uncle Harold a mission - to find out what happened. They embark on a journey, retracing the steps of Gunnar, Isaac’s long-lost father. As they venture to a place long forgotten below the waves, they will find mysteries that have been buried for eons. Yet, terrible secrets never stay hidden forever.
Playing as Isaac, you quickly find yourself in a dire situation - the world below the sea is the ruin of Sanctum, long-lost empire. Once there, you find that not one but two forces have their own dangerous intents. Whom can you trust and where will that trust leave you? Is the Sanctum technology still functional and what is it capable of? Finally, will you dare step into an entirely new world which might be nothing more than a place where you lose your life?
Source: The Developer Website.