Over the past several years, the X-Men''s worst enemies, from Sinister to Bastion to Magneto, have done everything in their power to discover all of the mutants'' secrets. Here, for the first time, the knowledge on Charles Xavier''s extended class that makes up the X-Men, Generation X and X-Force has been gathered into one place! But before this info can be deciphered, three X-Men will breach the most guarded sanctum of the U.S. government in a desperate attempt to destroy it! Not only will they discover things they could not have imagined, but they will also be confronted with a more immediate threat?a foe that could bring their world crashing down around them! It''s a full-length, action-packed story mixed with in-depth Handbook style entries with way-cool pin-up art by Salvador Larroca, Leinil Francis Yu, Michael Ryan, Sean Chen, Ariel Olivetti, Tom Raney and more!