Among the Stacks follows S., Head Librarian of the infinite Library which exists outside of time and reality, and contains every possible version of every possible story from across every conceivable reality. When S. awakes to find themselves alone within the infinite halls of the Library, they must brave the Library's infinite collections to try and find their colleagues. Their quest will take them to the Library's furthest reaches in search of answers and force them to grapple with the Library's slowly shrinking size, and what that means for the multiverse at large.