Series that explores the adventures the original X-men had during the 'gap' of reprint comics between Uncanny X-men issue 67 till issue 93.
Unlike other questionable comics of X-men adventures set in the past (like First Class), this series IS firmly set in continuity.
Translated into Spanish.
— Description from Comic Vine community (comicvine.gamespot.com · https://comicvine.gamespot.com/x-men-the-hidden-years/4050-9202/).
