Frank Miller's cover for Batman: The Dark Knight Returns #2 is expected to sell at auction next month for more than $500,000, The Associated Press reports.

While Heritage Auctions has sold other original art from the landmark 1986 DC Comics miniseries -- a page from Issue 3, featuring Batman and Robin in mid-air, fetched a record $448,125 in 2011 -- this is the first cover to ever appear at auction. It's also the only one from the four-issue series to be rendered completely in pen and ink by Miller, "with no significant painted elements or overlays." Heritage characterizes it as "artistically the best of the four."

“For fans of modern comics, this drawing is where everything really begins,” Heritage Vice President Todd Hignite tells The AP.“This moment defines Miller’s Dark Knight, and the modern day perception of Batman, like no other drawing.”

The auction also includes a 9.2 graded copy of 1940's Batman #1, which marks the first appearance of Catwoman and The Joker. A similar copy sold for $850,000 in 2012.

The record price paid at auction for a comic is held by a near-mint copy of Action Comics #1, which fetched $2.16 million in 2011. Online bidding is expected to begin July 12, with the auction held Aug. 1-3 in Dallas.