Warhammer: Glottkin Book 1 is a 128-page volume which provides a narrative sweep of the events surrounding the Chaos invasion of the Old World led by the Brothers Glott.
Warhammer: Glottkin Book 2 is a 64-page volume that contains six new scenarios and new rules based on the events in Warhammer: Glottkin Book 1. It includes the rules that will allow you to field the Glottkin, Maggoth Lords, Gutrot Spume and the Putrid Blightkings in your games of Warhammer. It also includes all-new rules for Karl Franz Ascendant (who is changed by the horrors of the End Times, but you will have to read the book to find out more) and Festus Empowered.
Armies of the End Times can field more Lords - up to 50% - and there are brand new rules for fighting battles in the streets of war torn cities. The new army list - The Legions of Chaos - allows you to create a unified army of Chaos drawn from Warriors of Chaos, Daemons of Chaos and Beastmen.