When Jason Ganos was asked to help sell an old box full of NES cartridges, he figured they would be pre-owned copies of games that had already been circulated in the market. He had no idea that he was about to make a historic discovery that would change his life forever.

Waukesha, Wisconsin is a suburb of the greater Milwaukee metropolitan area that boasts around 71,000 people. Its downtown center looks like it jumped straight out of the '50s, packed with old-fashioned soda shops, classic burger joints, and antique stores.

One of these stores is a vintage collectibles shop called OneStopWonders, owned by collector Kevin Braun. It’s got everything from VHS tapes, retro games, vintage clothes, and anything else a nostalgic Gen X / Millennial could want. Jason Ganos, owner of the website NintendoWire and an avid Nintendo fan, began working with Braun three months ago, initially helping him repair old pinball machines.

After learning of Ganos’ website, Braun asked him if he’d be willing to help him sell some video games that had been languishing in his stock. At first, these were fairly normal titles for the PlayStation, GameCube, and Super Nintendo — but then Braun hit him with a doozy.

According to the shop owner, a seller came into his store with a box of NES cartridges six years ago. These had somehow ended up with the seller’s grandfather, who supposedly worked for a precious metal recovery service. The seller claimed that Nintendo had wanted to get rid of its stock quickly, and rather than dumping the cartridges, sold them to the recovery service for a small sum, allowing the service to extract gold from the circuit boards.

Speaking to IGN, Ganos admitted that he found the tale a bit fantastical — but it wasn’t nearly as wild as what was actually in the box.

The rectangular box, outfitted with three stickers with both English and Japanese text, had been sitting in Braun’s storage unit collecting dust for the last six years. One of the box’s stickers said that it had been shipped on December 1, 1995, while another revealed what was stored inside: 100 pcs of Super Mario Bros. / Duck Hunt for the NES.

This came as a surprise to Ganos, who noted that Duck Hunt was a pack-in game that came with a purchase of an NES console. By December 1995, the NES was already fairly late into its life cycle, making things even stranger.

Inside the box were 97 individually-wrapped copies of Super Mario Bros. / Duck Hunt with a manual on the back of each cart. There’s no telling where the other three copies went, but Ganos was initially convinced that they couldn’t be very valuable, given that Duck Hunt was one of the most widely-distributed games for the NES. However, he was quickly proven wrong after uploading photos of the haul to a collector Facebook group, which he swiftly deleted after learning just how mind-blowing his discovery really was.

Ganos says that he was approached by a director of one of the world’s biggest grading companies, as well as a director of PSA Games, who both warned him that something “seemed off” about the carts and asked him to take extensive photos of the inside of one of the games, circuit boards and all.

“They both told me the same thing: ‘These are either fake, or these are brand-new, never-before-seen variants of these games,’” he told us. “Like, the back label is different. The manual has different language in the back. There’s different dates listed in the back of the manual. The motherboard is completely different. There’s text on the motherboard that is not on any known copies of Super Mario Bros. Duck Hunt.”

Judging by what they could see on the manual, these copies of Duck Hunt were manufactured in late 1993, making them the latest prints of the game that have ever been seen thus far. Naturally, this one-of-a-kind find drew lots of attention on the Facebook group, prompting him to take down the post and immediately contact PSA for authentication.

Mere hours later, Ganos was on a plane to California with a suitcase packed with all 97 cartridges, terrified they’d get confiscated by TSA or worse, dismantled by the agency. Luckily, that didn’t happen, and PSA was able to confirm that all 97 copies were totally legit. Not only that, but five of them were perfect 10s — a number that PSA had never given to an NES cartridge before. (The total breakdown is: 60 9.8s, 31 9.6s, five 10s, and one 9.4.)

Speaking with IGN, Head of PSA Video Games, Claire Shelton, described her thoughts after seeing the cartridges for herself.

“We were shocked,” she told us. “It almost felt too good to be true. We’ve looked at so many examples over the years. Our graders have graded hundreds of thousands of examples across all platforms, and it’s often the case with tens where you almost start doubting yourself. You’re like, ‘I must be missing something. There’s no way it could be perfect.’

“We look at so many things, and everything has at least some flaws, so for these to be as good as they were… we’re looking for perfection, or at least as close to it as you can come. Because with injection-molded parts, there’s always going to be pulloff lines right from where something is detached from a mold, or just the intricacies of manufacturing are going to leave things with a little bit of inconsistency. We were very grateful to be able to identify four of these that met that standard.”

The haul was so special that PSA serialized the entire collection, encapsulating each copy along with its manual, something the company has never done before.

But what makes these copies so special? The fact they were unopened straight from the manufacturer, that they were a new variant with a manual on the back of each cart, and that they boasted a bilingual back label," Shelton explained.

“There just aren’t very many of those, and for Nintendo to have gone out of its way to create a new variant for whatever reason, then presumably not letting any of those see the light of day… it would be pretty unusual for Nintendo to do a new sticker variant for literally 100 copies. You’d typically expect that number to be much, much higher, like into the thousands for revisions, especially for a game like Mario / Duck Hunt, which had many millions of copies sold in its lifetime,” she told us.

However, the MVP of these copies’ pristine condition wasn’t Braun’s temperature-controlled storage unit; Shelton said that if it hadn’t been for the plastic baggies that each cartridge was stored in, they would have most certainly been in worse shape.

“Even without movement, dust can cause scratches and micro-wear over time. If these had not been bagged, I feel confident saying that there would not have been any tens. Those bags did a whole lot of work,” she said.

Now, for the big question: What’s the dollar amount of these cartridges’ value? Shelton admitted that she couldn’t say for certain, but speculated they could land somewhere in the four-to-five-figure range.

“Four digits would be the floor,” she told us. “Multiple thousands of dollars, for sure. Given that the public will be able to ascertain that the 10 rate was roughly 4%, I think it could easily be in the five digits. I wouldn’t expect it to exceed the five digits, but I’ve been surprised before and I’d love to be surprised here. I do think this is the kind of thing that, given the novelty and if you’re a betting person, I wouldn’t expect more of these to show up, and the odds that they’re gonna be in better condition than these is also quite unlikely.”

On August 12, three of these cartriges will go up for auction through Goldin Auctions. The auction will run for three weeks, ending tentatively on September 9. Gason told us that he would also like to auction one of the carts off for charity, though no concrete plans for this have been set in place just yet.

“It feels completely surreal that this happened,” Gason admitted. “I think it makes it even more surreal that I happened to live in this tiny little small town, with this tiny little downtown area, with a tiny little retro shop, and I ended up making friends with the guy who had this thing in storage for six years.

“Nintendo has been a part of my life for as long as I can remember. And Mario Brothers Duck Hunt is the very first video game I ever remember playing, so it’s surreal and it’s fantastical, and I’m just happy that this all fell on my lap. It just feels really cool to be part of this type of Nintendo history.”

Virginia (she/her) is IGN’s News Editor. With ten years of experience reporting on games and entertainment, she’s got a storied background in the fighting game community, influencer news, and viral online trends. Find her on Twitter at @TheeMissGlaze.