Niantic Labs is mostly known for the game Ingress, and now the Google internal startup has announced its next project. The upcoming Endgame: Proving Ground is another immersive alternative reality experience, but this time it's part of a larger fictional world. This game will take place in the Endgame universe created with the help of author James Frey.
Endgame will be a trilogy of young adult sci-fi novels written by Frey, but so far only the first one has been published. The books will contain puzzles and clues that point the reader to a series of "keys" hidden in the real world. Niantic's augmented reality game will be part of the evolving story as players join one of the original 12 Lines of humanity. Details about the gameplay are spotty, but you'll have a champion that competes in virtual PvP battles with other players.
There is an interactive online hub available at AncientSocieties.com, where the story is already unfolding. Everything that's happening on this site and in the videos is completely in-universe, so it's going to sound insane on the surface. I assume reading the book will help bring everything into focus. The game will be out in beta later this year, and getting involved with the puzzles and challenges now will make it easier to get into the beta at that time.