Last year, as the game company Crytek went through near-catastrophic financial struggles, they found help from an unlikely source: the tech giant Amazon.

Amazon agreed to a huge licensing deal involving Crytek’s proprietary tech, CryEngine, according to four people familiar with the deal, all of whom spoke anonymously because they were not authorized to speak publicly about this arrangement. Though I haven’t been able to pin down the exact dollar figure—one source said $50 million; another said 70—sources say it was substantial enough to help Crytek recover from the financial difficulties that kept them from paying some staff for months, as we reported last year.

Last month, representatives for Crytek teased that the multinational company had struck a big licensing deal that helped save the company, likely a reference to this partnership with Amazon. “It was a huge one, probably the biggest one,” Crytek co-founder Faruk Yerli said in mid-March. “I can’t say anything more in detail, but hopefully we’ll be able to announce it with the partner soon.”

It’s unclear what Amazon plans to do with CryEngine, a powerful set of tools that has been used in all of Crytek’s games (Crysis 3, Ryse) and licensed to a number of external developers for games like Turtle Rock’s Evolve and the upcoming Bethesda free-to-play game BattleCry. As a game engine, “CryEngine” is essentially shorthand for a deck of middleware software including a graphics renderer, a physics engine, and other development tools all created by Crytek’s engineers to facilitate game-making. (For an example of what a powerful game engine can do, check out this recreation of BioShock in CryEngine 3.)

Amazon may have licensed out the engine to use for their games, or, as some sources have suggested, they may be using it as a baseline to build their own proprietary gaming engine.

Whatever the specific details here, this is yet another sign that Amazon has big plans in the world of video games. Last year, the tech giant poached Portal lead Kim Swift and Far Cry 2 designer Clint Hocking to work on top-secret projects that still haven’t been announced. Amazon also purchased Double Helix, the development studio behind 2013’s Killer Instinct. In April of 2014 they launched an Android-based gaming and streaming console, the Amazon Fire TV, but it failed to make much of an impact on the video game world, even after they snagged the infamous Flappy Bird as an exclusive. Most industry observers believe Amazon has grander ambitions for gaming.

Representatives for Amazon and Crytek did not return requests for comment.

You can reach the author of this post at jason@kotaku.com or on Twitter at @jasonschreier.