In a series with the MCU’s scope (23 films and counting) and stakes (fate of the universe), it can be easy to lose track of what’s important. Luckily, from the beginning of their run, Kevin Feige and the rest of the Marvel team established a very simple rule: If it’s shiny and blue, you better keep your fuckin’ eyes peeled.

The Shiny Blue Object (SBO) immediately became an essential part of the Marvel story when it became the literal heart of its first hero. Iron Man’s arc reactor saved his life and blazed a trail for what all future SBOs were capable of.

In the next meaningful MCU film (sorry Incredible Hulk), Odin’s vault holds a bright blue cube capable of decimating the populations of entire planets. Somehow this cube is not the Tesseract.

Considering that the movie treats Loki escaping with the Casket of Ancient Winters as a significant event yet it plays no role in future films, it’s clear that the producers had not yet decided that another SBO would replace it as the preeminent blue cube of the MCU.

Introduced in Captain America: The First Avenger, the Tesseract is the ultimate SBO. It’s got everything: plot importance, history with multiple heroes, vague cosmic powers that won’t be explained for like eight movies. In Captain, it basically acts like the Ark of the Covenant by serving as a mysterious plot device then (almost) killing the bad guy that had been hunting it. As the MCU progressed, the Tesseract became arguably the most important Infinity Stone, unleashing Loki’s Chitauri army on NYC, powering Captain Marvel, and enabling Thanos’ easy transport to the other stones. 

You might’ve thought the SBO’s dominance in Marvel Land would end with the introduction of the rest of the Infinity Stones. After all, the other five stones are equally powerful and are all different colors. Let’s take a look at the second Infinity Stone to appear in the series…

That, my friends, is the Mind Stone. Marvel’s boner for SBOs is so strong that the Mind Stone, which is unquestionably yellow, appears in The Avengers as a shiny blue orb at the end Loki’s scepter. Is it confusing that both of the stones Loki has possessed appear to be blue? Very. Does Marvel care? Fuck no.

Marvel’s zeal for SBOs extends well beyond the Phase One films into the recent blockbusters: the Great Mound of Wakanda, Thor’s vest and axe, and Ego’s internal organs, just to name a few examples. While I don’t know what the future films have in store, don’t be shocked if, after his final defeat, Thanos is engulfed in radiant blue light. I don’t know where it’ll come from, but I know it’ll be cool as hell.