House of M Prelude - Excalibur (2005)

Collects Excalibur (2004) #11-14.
Callisto answers a cry for help from Warren Worthington, a.k.a. Archangel! But Callisto and Warren have some pretty unpleasant history between them...can they overcome their differences long enough to survive? Meanwhile, Professor X and Magneto struggle to help their disturbed guest on Genosha.