From the back cover:
The past can come alive!
Ancient empires, horrors, miracles, catastrophes... Mystara's past is a rich treasure trove of such experiences, just waiting to be plundered. Most Player Characters learn about history from musty scrolls and crumbling clay tablets... but no more. Now they can live through those ancient mysteries directly.
Within these pages you will find adventures that span from mere decades before the modern era, all the way to the remote beginnings of humankind itself. While Geoff Gander and OldDawg explore two of the oldest human empires, LoZompatore delves into the origin of the elves. Other articles focus on darker times, in ancient Taymora, and we even delve into the past of the Mystaran community itself in an interview with James Mishler.
Even more can be found within, for this isn't the end of the story. Nor is it the beginning. You can always go... further back...