The first supplement published for Ars Magica 5th Edition was The Broken Covenant of Calebais (AG0275, ISBN 1-58978-071-X). This book sold out back in 2005, after only about a year on the market, but we are pleased to be bringing it back into print using digital ("print on demand") printing. Errata in the book have been corrected and the price has been increased to $22.95.
We expect to receive a shipment of Calebais at the same time as the new Lords of Men supplement and the Unknown Armies core rulebook reprint. Your favorite local game store should be able to get it by the end of May.