For the last 10 years, dozens of Marvel superheroes have tried to keep powerful stones out of the hands of the bad guys. But these Infinity Stones are more than just MacGuffins in the Marvel Cinematic Universe timeline. When combined, these six powerful gems—the Space Stone, the Mind Stone, the Reality Stone, the Power Stone and the Soul Stone—can be wielded to destroy half the universe. That’s exactly what Thanos, the bad guy in the upcoming Marvel movie Avengers: Infinity War wants to do.
If you’re a little fuzzy on where our heroes encountered these gems, who those heroes were and where their biggest battles fell in the Marvel Cinematic Universe timeline, we’ve got you covered. We’ve recapped every movie, dated every important event and highlighted all the Infinity Stones. (Marvel hasn’t always been super specific about the Marvel Cinematic Universe timeline, so we did our best to estimate when everything took place.)