With the earlier publication of The Amber Spyglass, it seemed that Philip Pullman had finished his involvement with Lyra and the other characters of His Dark Materials. Thankfully, Lyra's Oxford shows that is not the case, and far from being just a tacked-on addition to that series, it's a full story in it's own right and also possibly a tantalising teaser for The Book of Dust, whenever it finally arrives.
The story within the book ('Lyra And The Birds') is an interesting tale of itself, excitingly detailing Lyra and Pantalaimon's dangerous trip across Oxford to help a witch's daemon. It's similar to the early chapters of Northern Lights, with Lyra front and centre, surrounded by fascinated descriptions of Pullman's strange alternate Oxford.
However, it's the other ephemera that really make the book a must-read and turn it from being just a story into a true mystery. Children and adults alike will have lots of fun looking over the map and the other items, looking for little clues that cast new light on both the story and His Dark Materials, making this book into a bridge between His Dark Materials and The Book Of Dust.