S1, E2: The Librarians have retrieved King Arthur's Crown - only to discover it's part of a deadly trap laid by their ancient enemies, the Serpent Society. Now the Library is lost in space and time, Flynn is mortally wounded, and Dulaque has recovered the real key to his scheme: Excalibur, King Arthur's magic sword. On the run, the Librarians retreat to a small safe house, an Annex to the Library, run by the brilliant and cranky Jenkins. The Librarians must stop Dulaque from bringing magic back to the world - but they have to break into Buckingham Palace to do it.