Fans who stayed through the first part of the credits of "Thor: The Dark World" got one hell of a teaser about where the Marvel cinematic universe is heading next.

Spoilers ahead!

It would be easy to assume that Benicio Del Toro showing up as his "Guardians of the Galaxy" character, the Collector, would be enough of a tease to whet the appetites of fans until next August, but he drops a clue that we think will be integral to the future of the series.

As Volstagg explains to the Collector, Asgard is already housing the Tesseract from "The Avengers," and it would be safe to also hold onto the Aether, another "Infinity Stone". (That noise you heard in the theater was nerds gasping for air.) As those comic book fans would tell you, once they catch their breath, the Infinity Stone -- or Infinity Gems, as they're more commonly referred to -- have played a major role in the Marvel comic books since the 1970s, and they have deep ties to a villain that fans have been waiting years to see in action.

The Infinity Gems are powerful stones, each with its own specific power and made from the remains of an omnipotent god that committed suicide. They were originally held by the Elders, ancient and powerful beings that inhabit the Marvel Cosmic Universe. In the lead-up to one of Marvel's most famous storylines, "The Infinity Gauntlet," Thanos, the villain teased at the end of "The Avengers," took the stones from the Elders, embedding them all into a golden glove. Thanos then used the Infinity Gauntlet to blink half of all life in the universe out of existence in order to please the object of his obsession, the physical personification of death in the Marvel universe.

What does this mean from the upcoming Marvel Studios movies? With the Collector's hands on one of the Infinity Stones and Thanos confirmed to appear in "Guardians of the Galaxy," you can bet that Star-Lord, Gamora, Rocket Raccoon, Drax and Groot will be involved in the quest for the rest of powerful artifacts.

When we spoke with Marvel Studios co-president Kevin Feige at the junket for "Thor: The Dark World," he explained that, like Samuel L. Jackson's cameo at the end of "Iron Man," this teaser is as much a nod to comic fans as it is a sign of things to come.

"The best Easter eggs do both. Nick Fury at the end of 'Iron Man,' for people who knew who he was, that was a nice Easter egg, but it was also informing the audience of what's to come," he said. "So certainly the Infinity Stones and revealing that the Tesseract and the Aether are Infinity Stones. Comic fans perhaps know where that's going, and people who don't know that from the comic lore, I hope, will start to learn."

"Thor: The Dark World" is in theaters now.