Actor has some catching up to do on the classic Marvel bad guy, but raves for James Spader, who'll play his big-screen foe.

Chris Hemsworth may have a bit of homework to do before he starts shooting the "Avengers: Age of Ultron," Marvel's highly anticipated sequel due in 2015. Because as the man behind Thor revealed during an interview with MTV News at the Toronto International Film Festival, he isn't exactly familiar with the villain at the center of the upcoming blockbuster.

"I haven't had to look into it and understand it yet," Hemsworth admitted when MTV News' Josh Horowitz asked if he knew what Ultron was. "With all honesty, I have no idea."

To be fair, the cast didn't even know the film's title until it was revealed this past July at San Diego Comic-Con. But while Ultron may still be a mystery to castmembers like Hemsworth, he did know one thing: The main villain will be played by Emmy award-winning master of creepiness James Spader.

"He's great," Hemsworth said of his new co-star. "He's awesome."

Still, Hemsworth admitted that he hasn't met Spader in person yet, and after running through his itinerary for the rest of 2013, it became clear that "Avengers: Age of Ultron" is still far in the future for the actor.

"The whole Avengers thing is now starting to come up in conversations and I'm like, 'God, I've still got another film to shoot and 'Thor 2' hasn't even come out yet. This ['Ultron'] script's not even written yet. I know [screenwriter] Joss [Whedon] is [writing it now]."

Fans can see Hemsworth next as the British Formula One racing champ James Hunt in the Ron Howard-directed "Rush," a film based on the true events of the 1976 racing season. Hemsworth also touched upon another potential franchise based around the 2012 hit "Snow White and the Huntsman," saying that a follow-up will happen if there's an appetite for more.

The actor's superhero alter ego next takes the screen in "Thor: The Dark World," which pits Hemsworth against the evil dark elf Malekith (Christopher Eccleston). It's a threat so big that it forces Thor to team up with his no-good brother Loki, played by Tom Hiddleston. The film will also expand on the god of thunder's relationship with Jane Foster, the human scientist played by Natalie Portman, as she travels across the rainbow bridge into Asgard.

"Rush" opens in theaters on September 20, while "Thor: The Dark World" hits theaters on November 8.

Check out everything we've got on "Avengers: Age of Ultron."