The first Infinity Stone we encountered in the Marvel Cinematic Universe was the Space Stone, which initially appeared back in 2011’s Captain America: The First Avenger. Back then, though, the Macguffin was referred to as the Tesseract, with it not becoming clear until many movies later that it was actually one of the six powerful gems. It turns out this wasn’t originally the plan, however, according to Avengers: Infinity War‘s screenwriters.
Scribes Stephen McFeely and Christopher Markus were talking with Collider in an in-depth interview when the topic of Red Skull’s return in the movie, his first appearance since The First Avenger, came up. While discussing this, the writers revealed that the Tesseract was initially talked about behind the scenes as the Cosmic Cube, the long-running reality-warping box from the comics.
“Obviously, we started with him, 10 years ago. And he had the Cosmic Cube, which was then referred to sometimes as the Cosmic Cube, and we didn’t know it was one of the Infinity Stones.”
Some fans might be surprised to know that it wasn’t always the plan to introduce the Infinity Stones into the MCU, so as to build up to Thanos’ hunt for them in what became Infinity War. In actual fact, this overarching plotline wasn’t on the table until director Joss Whedon decided to include the Mad Titan in the final moments of The Avengers. After that, the Marvel team began to introduce the gems – and, apparently, retcon the Tesseract into becoming one.
As we said, the Cosmic Cube has been the focus of many storylines over the decades on the page, but seeing as it’s now been merged with the Space Stone in the MCU, we don’t expect it to play a major role after the heroes presumably rule out the threat of the Infinity Stones in Avengers 4, the sequel to Infinity War which arrives next May.