One of the most important Avengers keys of the Silver Age, Avengers #55 (1968) reveals that the mysterious Crimson Cowl is actually Ultron-5, marking the first appearance of Ultron, one of Marvel’s most iconic Avengers villains.

Written by Roy Thomas with art by John Buscema and George Klein, this issue also features appearances by Whirlwind, Radioactive Man, Melter, Klaw, and the Black Knight, making it a major storyline in Avengers history.

Ultron has remained a central antagonist in Marvel comics for decades and gained worldwide recognition following his role in the Marvel Cinematic Universe film Avengers: Age of Ultron.

Because of Ultron’s importance within Marvel continuity, this issue is widely considered one of the key Avengers books of the late Silver Age.

This CGC 5.0 Off-White Pages copy offers collectors an accessible example of this important Marvel key issue.