This book expands so much on Mage the Awakening 2nd Edition and I shall do a quick summary based on chapter detailing a lot about what it does to make you want to ingest everything within the confines of this book.
Chapter 1 - We get details about the Supernal Entities presenting us with some of the boons these powerful beings can bestow as well as some of the explanation of what "Iron Seals" are to the Seers and how they came about their discovery. We also learn a little more about the Ministries and how they operate. We also get a more indepth explanation of how the Supernal Realms represent the other Arcana and explaning why the Inferior are inferior and how they are Inferior for each Path. We get expanded mechanics on Mystery building for Focused Mage Sight as well as some very cool merits to expand on the capability of the most widely used tool of a Mage in their daily and supernatural lives. We also learn more about the mysterious Aedes and how they affect the world around them and the Mages that investigate them, very cool mysteries to add to any chronicle.
Chapter 2 - Details more about Yantras including those that are not simply a wand or an artifact discovered by the Mage but through their actions and use of magic to create very different and useful Yantras based on specific needs. Yantras are a big part of making spells work and is such a great thing to have expanded upon in ways that don't always include Merits and you can have 2 dedicated tools!
Chapter 3 - Gives some much needed errata on Imbued Items as well as goes into detail with various other ways of crafting Imbued Items along with the use of Soul Stones and also finally gives more information on the Perfected Materials that have only been teased or hinted at with 1st Edition.
Chapter 4 - Goes into the art of creating grimoires and palimpsest to make spells more powerful or add new elements to rotes making them unique and much more useful when compared to standard rotes.
Chapter 5 - Goes into artifacts and the various types expanding on their mechanics and usefulness to Mages explaining why their are such coveted items and the different kinds that might be used by the Seers.
Chapter 6 - Goes into the Awakening itself, laying down the mechanics/system necessary to produce an Awakening while also leaving several more mysteries about Mages that awaken to the same watchtower or awaken at the same time to the same Path and how this changes and effects them.
Overall, an incredible book that expands on a lot that we have desired in Mage the Awakening since 1st Edition.