Published Oct 1991 by Marvel.

48-page giant. Cyclops/Wolverine/Iceman cover. Cover pencils by Jim Lee, inks by Scott Williams. Rubicon, script by Jim Lee (Co-Plot) and Chris Claremont, pencils by Jim Lee, inks by Scott Williams; Magneto forms the Acolytes and proclaims Asteroid M a haven for mutants everywhere; But the rest of the world doesn't see it that way; Nick Fury cameo. 2-page pin-up: gallery of X-Men villains. X-Men Sketchbook by Jim Lee. NOTE: Cover C connects to covers 1A, 1B, and 1D to form a single giant image.

First appearance of the two Blue and Gold X-Men teams lead by Cyclops and Storm.

First appearance of The Acolytes.

Featured Characters:
X-Men
Professor X (Charles Xavier)
Blue Team (First appearance)
Cyclops (Scott Summers)
Wolverine (Logan)
Beast (Hank McCoy)
Gambit (Remy LeBeau)
Psylocke (Betsy Braddock)
Rogue
Gold Team (First appearance)
Storm (Ororo Munroe)
Jean Grey (Joins)
Archangel (Warren Worthington III)
Colossus (Peter Rasputin)
Iceman (Bobby Drake)
S.H.I.E.L.D.
Nick Fury
Banshee (Sean Cassidy)
Forge
Moira MacTaggart
Magistrates
Tam Anderson
The Acolytes
Magneto (Magnus)
Fabian Cortez
Delgado
Anne-Marie Cortez
Chrome
Nance Winters

A group of mutants have stolen a shuttle and are being pursued by some agents. Magneto arrives and tears their ships apart before bringing them on board Asteroid M. At the mansion the X-Men are testing the building's defenses. They split into two teams, but only Wolverine, with Psylocke's help, is able to breach them. The two different crews fight on board the Asteroid until Magneto stops them. One of them, Fabian Cortez, has a suggestion for Magneto. Back at the mansion the X-Men Blue team respond to a signal that Magneto is up to something. He has raised a nuclear submarine.