A monumental Silver Age milestone featuring the historic first appearance of the Kree Sentry (Sentry 459), a pivotal element that deeply expanded Marvel's cosmic lore. Titled "The Sentry Sinister!", this book also includes vital appearances by Crystal, Triton, and Lockjaw of the Inhumans. The imposing back-shot cover of the Sentry looming over the team is a standout Jack Kirby and Joe Sinnott composition, matched internally by Stan Lee's foundational script. Certified at a CGC Universal Grade 7.5 (Very Fine Minus) with White Pages, this sharp copy is a vital addition for cosmic Marvel investors.