If you’re a little fuzzy on all 18 movies in the Marvel Cinematic Universe, the heroes at ScreenPrism have made the perfect video explainer to help get you ready for Avengers: Infinity War this Friday. Even better, it’s under 15 minutes, which makes it perfectly suited to help pass the time when you’re waiting on line or bored by the pre-movie trivia.

On Tuesday, ScreenPrism uploaded a 15-minute explainer on the Infinity Stones, the all-important space rocks that Thanos (played by Josh Brolin) seeks in Infinity War. ScreenPrism breaks down all the Infinity Stones by power, color, and what movies they appeared in. The video also explores the hidden symbolism in each Infinity Stones.

For example, the Space Stone also known as the “Tesseract” — seen in 2011’s Captain America: The First Avenger and 2012’s The Avengers, and for a brief moment in 2017’s Thor: Ragnarok — is a metaphor for war, which is “inherently about negotiating the spatial boundaries between different nations or realms.” Throughout the MCU, the Tesseract has been used to build weapons, and ScreenPrism makes a compelling case that war is all about big players dominating space at the expense of everyone else. That’s a pretty sharp microcosm of big superhero battles.

Meanwhile, the Aether, or the Reality Stone (seen in 2013’s Thor: The Dark World), takes on a liquid form, evocative of a virus that infects individuals, as seen by Natalie Portman’s Jane Foster, an astrophysicist who places her faith in concrete evidence and data. In many ways, the fact that she’s “infected” by the Reality Stone represents how our reality “is shaped by bigger, cosmic, unknowable forces.” In short, there is a lot more to reality than we understand.

The whole video is worth a gander, and is available on ScreenPrism’s YouTube channel. Queue it up and hit play when you’re cozy in your seat — just remember to turn off your phone when the movie starts.

Avengers: Infinity War hits theaters April 27.

Photos via Marvel