From the publisher's website:-
A recent find at Miskatonic University has unearthed even more mysteries pertaining to the strange happenings in Arkham, Massachusetts. While the worshippers of the Ancient One grow in strength, the stalwart defenders of this sleepy town are put to the ultimate test.
Miskatonic Horror is a new type of Arkham Horror expansion that builds upon the materials found in the ample library of other Arkham Horror expansions. While the components and rules found in Miskatonic Horror can be enjoyed with only the Arkham Horror base game, the more expansions you incorporate, the more aspects of Miskatonic Horror you can enjoy.
Miskatonic Horror adds nearly 450 new cards and several new sheets, including:
New Skill, Gate, and Mythos cards for the Arkham Horror base game
Additional Exhibit Item cards for Curse of the Dark Pharaoh
New Injury, Madness, Dunwich Location, and Dunwich Horror cards for Dunwich Horror, as well as an all new Dunwich Horror Herald sheet
More Blight and Act cards for The King in Yellow
New Kingsport Location, Epic Battle, Blessings of Noden, and Visions of Hypnos cards for Kingsport Horror
Over 20 new Cult Encounter cards for The Black Goat of the Woods
New Innsmouth Location and Innsmouth Look cards for Innsmouth Horror
Additional Relationship cards and Reckoning cards for Lurker at the Threshold
Plus new Player Reference sheets and a new Institution variant!