Reportedly due to a pricing error, the Xbox One version of Fallout 4 (and its DLC) was free today for a period of time through the Xbox Store, though Bethesda says it has “no idea” how that happened.

Earlier today, the base game and expansions Automatron, Wasteland Workshop, and Far Harbor were all offered for the low, low price of zero dollars from the digital store. Here’s a tweet from Twitter’s Wario64, who brought this to our attention earlier today.

What’s going on here? Bethesda marketing VP Peter Hines was asked about it on Twitter. He said he’s not sure how it happened, but suspected it was a bug.

“No idea,” Hines said. “Not my platform. Bug/hiccup. They’ll undo it.”

Indeed, Microsoft has. Fallout 4 and all of its DLC have returned to their normal price points. There is still no word yet from Microsoft on how this happened.

In other news about Fallout 4, Bethesda has shared its plans for improving mod support. Looking ahead, if the developer is to make more Fallout-related announcements, that could happen during Bethesda’s E3 2016 briefing this coming Sunday, June 12.