A rare Superman comic book is expected to sell for over £2 million next month.
The first edition of Action Comics - which featured the iconic superhero lifting up a car on its cover - was bought for the equivalent of £1.50 back in 1938 but there are now believed to be just 77 surviving copies from its 200,000 print run.
A Heritage auctions spokesperson commented: "It's the best copy of Action Comics No 1 we have ever offered and already the most valuable by far.
"It is the book in which Jerry Siegel and Joe Shuster introduced readers to Clark Kent and Lois Lane and ushered in the era of the Superhero."
Meanwhile, the auction house's senior vice president Ed Jaster described the item as a "truly unique find".
He added: "This treasure has never left the family of its original purchaser."
In the issue, Superman - who has been played by the likes of Christopher Reeves and Henry Cavill on the big screen - discovers his powers but uses them to "benefit mankind", and rescues Lois from a gangster.
The comic is seen as hugely significant, and back in 2018 DC Comics president Paul Levitz hailed it as "the singular most important comic book published in America".
Another copy of Action Comics No. 1 was sold for a record £2.4 million ($3.25 million) in April this year.
Meanwhile, live bidding for the current item - which is said to be in fantastic condition - has already hit £1.1 million ($1.5 million), and the Dallas, Texas sale is running until January 13.