A view of a DC Comics, Superman No. 1 issue is shown Monday, Nov. 24, 2025, in Irving, Texas. (AP Photo/Tony Gutierrez)

A copy of the first Superman issue, unearthed by three brothers cleaning out their late mother’s attic, netted $9.12 million this month at a Texas auction house which says it is the most expensive comic book ever sold.

The brothers discovered the comic book in a cardboard box beneath layers of brittle newspapers, dust and cobwebs in their deceased mother’s San Francisco home last year, alongside a handful of other rare comics that she and her sibling had collected on the cusp of World War II.

Lon Allen, vice president of comics at Heritage Auctions, traveled to San Francisco earlier this year to inspect their copy of “Superman No. 1” and show it to other experts for appraisal.

The “Superman No. 1” comic, released in 1939 by Detective Comics Inc., is one of a small number of copies known to be in existence and is in excellent condition.