Cogman’s latest jumps into the action after 2020’s The Dark Archive. While still reeling from the revelations about her own origins, librarian, spy, reluctant diplomat, and all-too-human Irene Winters finds herself strong-armed into a secret mission to either bring down the Library’s greatest enemy, figure out why entire worlds are going missing, outrun the agents who believe that she’s gone rogue, save her lover Prince Kai (who’s a dragon) from the machinations of his own family, and save the Library from the rot that lies at its own dark heart. Just another day saving the universe for the intrepid Librarian Irene and her friends. “Invisible Library” newbies would do well to start at the beginning, while long-term readers will be on the edge of their seats following the events in this thrilling conclusion to a fantastic series. VERDICT Irene’s madcap adventures are played for the highest stakes in the epic conclusion to the long-running series plumbing myths, folklore, spies, and skullduggery.