Marvel gave fans of their cinematic universe their first glimpse of the central villain of Avengers: Age of Ultron last October, but the highlight of the film’s second trailer is a surprising battle between two of Earth’s Mightiest Heroes. In addition to protecting the planet from Ultron, Tony Stark’s crime-fighting creation gone horribly wrong, it seems the Avengers will have to take on a rampaging Hulk.

The new trailer, which was released on Monday, continues to show how much of a threat Ultron will present to Iron Man, Captain America, Thor, Hulk, Hawkeye and Black Widow in the highly-anticipated follow-up to 2012’s The Avengers. 

“No matter who wins or loses, trouble always comes around,” said a somber Nick Fury, played by Samuel L. Jackson.

“We have no place in the world,” said Scarlett Johansson’s Black Widow.

Viewers get to see Ultron beating up on and strangling Chris Evans’ Captain America, whom he promises to “tear apart from the inside.” The new trailer also shows Iron Man being blasted through a wall by a red beam of light presumably emitted from the insane robot, and a number of terrifying explosions. While Ultron is undoubtedly the main source of conflict for the Avengers in the film, the second trailer reveals that they’ll also spend a good portion of the film fighting among themselves.

“You’ve meddled in something you don’t understand,” Chris Hemsworth’s Thor tells Robert Downey Jr.’s Tony Stark before grabbing him by the throat and lifting him into the air.

Thor’s anger with the billionaire playboy can be easily justified, since it was Stark who built Ultron in the first place, hoping that it would be able to combat potential enemies too powerful for the Avengers. The more confusing fight is the one between a Hulkbuster-armored Iron Man and the Incredible Hulk. A bizarre redness in the Hulk’s eyes implies he may be under the influence of another superpowered being – such as Elizabeth Olsen’s telepathic Scarlet Witch – but viewers will likely have to wait until the film comes out on May 1 to find out.