From publisher description:
Heroic Co-operative Deck-Building!
The Tower of Secret Lore is the acvademy where all mages are taught, and where the Council that keeps them in order meets and works. The main tower is host to an almost impossible number of floors, with huge buttresses and parapets reaching out from it and containing entire rooms themselves. Shining with crackling magelight, it is an unmistakeable landmark.
More Spells, More Problems
The Tower of Secret Lore is a new Location deck, fully compatible with other Bulwark decks. Its defence presents new challenges for experienced Bulwark players, but it equally suitable for new players. It has particular synergy with the new Hero decks Magister Kelemen, Magistra Csenge and Jakab Startouched.