"Supernovas, Part 2"
*Mike Carey and Chris Bachalo take over the X-Men, or at least what’s left of them! As old threats are still having their effects, new, more deadly threats emerge from the unlikeliest of places. Threats that spell doom for the X-Men. Plus, what could possibly strike terror into the heart of...Sabretooth!? And who are The Children? This is the book you’ve been waiting for! A perfect starting point for any new reader! *Source: marvel.com
Professor X in this comic is actually Mystique in disguise.
Also includes a Masked Marvel back-up story.