As the X-Men embark on their inaugural world tour, they must confront some unsettling truths about their mentor, Professor
Charles Xavier. Before founding his school for young mutants, Xavier abandoned his only son, David, a mutant with uncontrollable
reality-warping abilities. Now, David has returned, looking to exact revenge on the father who left him - and he's willing
to eradicate anyone who stands in his way. Will the X-Men be forced to kill Xavier's son to end his threat against the world?
Following the tragedies of their world tour, the X-Men seek the calming protection of Xavier's school - but their suspicions
of his methods only increase. Xavier's mental blocks on student Jean Grey's psychic abilities continue to crumble, and she
grows increasingly unstable - plagued by visions of a world engulfed in the flames of a fiery phoenix. When the X-Men finally
meet Xavier's mysterious financial backers, Jean's hallucinations become reality as the otherworldly Phoenix takes possession
of the teenage telepath. Also included in this volume is a bonus tale of Gambit, a Cajun street hustler who must use his mutant
gifts to protect a homeless boy in great danger.
This title collects "Ultimate X-Men" numbered 13-20.