This is a rare and highly sought-after comic book, featuring the first cover appearance of the villainous Mister Sinister. The comic is professionally graded by Certified Guaranty Company (CGC) with a grade of 9.6 Near Mint+ and has white pages. The issue number is #239 of the Uncanny X-Men series, published by Marvel Comics in December 1988 during the Copper Age of comics (1984-1991). With Marc Silvestri's cover art and Chris Claremont's writing, this comic book is a must-have for any X-Men fan or comic book collector.