FANTASTIC FOUR #28

Cover shows moderate wear consistent with a mid-grade Silver Age book: soft corners, some edge wear along the right and bottom borders, light surface soiling and toning to the cover paper, and a faint diagonal crease/scratch running through the lower right quadrant of the artwork. A pencil price notation is visible in the upper right of the cover art. The book is in a protective sleeve, and no spine roll or major tears are apparent from this angle, though the spine stress could not be fully evaluated due to the mylar bag glare. Interior pages and back cover were not assessed.

Fantastic Four #28 (July 1964), by Stan Lee and Jack Kirby with inks from Chic Stone, introduces the Mad Thinker, a calculating strategist who would become one of the team's recurring intellectual antagonists, deploying his Awesome Android in a scheme against the FF. The issue is further distinguished as the first crossover appearance of the X-Men outside their own title, teaming the mutant team with the Fantastic Four only months after the X-Men's debut, an early instance of Marvel's shared-universe cross-pollination that Lee and Kirby were pioneering at the time.

The book trades as a durable mid-tier Silver Age Marvel key, with deep census population reflecting decades of steady collector interest rather than short-lived speculation. Pricing climbs sharply above the 9.0 threshold, with 9.4 copies already commanding a firm four-figure premium over the bulk of the graded population, and the near-total absence of 9.8s on census underscores how difficult this issue is to find in true gem condition, likely a function of period paper stock and handling common to 1964 Marvels rather than print rarity.

Demand centers on FF and X-Men crossover completists, Silver Age Marvel key-issue collectors, and dealers assembling runs anchored by Mad Thinker's debut. Lower and mid grades move steadily as affordable entry points into the FF #1-40 run, while high-grade certified copies, especially anything approaching 9.6 or better, are scarce enough that transactions are infrequent and priced individually rather than off a liquid market, making census-topping copies a target for grail-level Silver Age portfolios.