The Invisible Library by Genevieve Cogman is an intriguing gaslamp fantasy novel that combines elements of fantasy, mystery, and adventure. The story follows Irene, a librarian who works for the mysterious Invisible Library, which exists outside of time and space. Her mission is to retrieve rare books from different realities, but when she is sent to an alternate London, she becomes entangled in a dangerous game of wits. This book offers a unique blend of fantasy and literary references.