Former Superman artist Al Plastino was startled to learn his original artwork for "Superman's Mission for President Kennedy" is up for auction — and not in the John F. Kennedy Memorial Library, as he had been led to believe.

According to the New York Post, Plastino was at New York Comic Con when he learned another exhibitor had the artwork, and that Heritage Auctions was scheduled to sell it (with a starting bid of $20,000 per page) on Nov. 22, the 50th anniversary of Kennedy's assassination. Plastino, who is 91 and has prostate cancer, posted a plea for help on his Facebook page, and the comics community quickly responded with offers of legal help.

Plastino drew the story "Superman's Mission for President Kennedy" in 1963 to promote Kennedy's physical fitness program, as part of a collaboration between DC and the Kennedy administration. The issue was scheduled to go on sale in late November, but editors quickly pulled it and substituted other material when Kennedy was assassinated. Shortly afterward, President Lyndon Johnson's staff asked DC to go ahead and run the story, which they did, adding a special commemorative page showing Superman saluting a ghostly image of Kennedy.

After the story was done, Plastino said, his bosses at DC were supposed to donate the original artwork to the Kennedy library. It's not clear what actually happened, but the library has no record of ever receiving the pages, and the current owner acquired them in a Sotheby's auction in 1993 for $5,000. "We have no reason to believe our consignor does not have the right to sell the piece, and nobody has shown us any evidence that he doesn’t," Heritage's senior consignment director, Steve Borock, told the Post. Borock also responded on Facebook, saying, "We have no reason to believe our consignor (One we have known for many years and who has an excellent track record with us) does not have the right to sell the piece, and nobody has shown us any evidence that he doesn’t ... We’re all very sorry to hear that Al Plastino never got the art back from DC, but we all know the sad realities of the comic publishing business back in those days. Heck, it’s one of the reasons I am on the board of The Hero Initiative and the reason Heritage helps support them."

Nonetheless, Heritage has put a hold on the auction, and Neal Adams's daughter Kris Adams Stone says a legal action is being prepared to stop it all together. She argues that Plastino did not sell the actual art to DC — "He never gave up ownership of the art because DC never purchased it from him or paid sales tax" — so it still belongs to him.