There can be only one, after all. In Season 4 of The Librarians, Flynn Carsen (Noah Wyle) receives a dire warning from the past that there can only be one Librarian lest a civil war break out among the Librarians once again. This pushes Flynn to make a dire decision of his own and Eve Baird (Rebecca Romijin) to make a choice she doesn't want to make. Her hesitancy causes the Library to put the team on trial to decide which one will finally take on the mantle of the one and true Librarian. The trial, however, leads to unexpected consequences that threaten the very existence of the Library itself. <p> A direct spin-off from The Librarian film series, the TV series features fan-favorite characters and continuity of plot lines with the films.