Took them long enough, but Marvel has finally confirmed that Aaron Taylor-Johnson and Elizabeth Olsen are joining the cast of Joss Whedon’s The Avengers: Age of Ultron, which opens May 1, 2015.

Taylor-Johnson, formerly seen in the Kick-Ass films (2010, 2013) and Oliver Stone’s Savages (2012), will play one half of the brother-sister duo of Quicksilver and Scarlett Witch, with Olsen playing the other. Olsen was last seen in Liberal Arts (2012) and Kill Your Darlings (2013). Both actors also star in the remake of Godzilla, along with Bryan Cranston of the AMC drama series Breaking Bad; the film is set to open May 15, 2014.

From Marvel’s press release:

Screen Shot 2013-11-25 at 10.34.05 AMAaron Taylor-Johnson and Elizabeth Olsen have officially joined the Avengers family as the brother-sister duo of Quicksilver and Scarlet Witch in Marvel’s “Avengers: Age of Ultron,” the highly-anticipated sequel to 2012′s smash-hit “Marvel’s The Avengers”! “Avengers: Age of Ultron” arrives in theaters May 1, 2015.

“Avengers: Age of Ultron” will bring the Marvel Universe’s biggest heroes together again to face one of their biggest villains, with “Marvel’s The Avengers” director Joss Whedon returning to write and direct the sequel. “Marvel’s The Avengers” was released in 2012 and went on to earn $1.5 billion worldwide, making it the third-largest grossing movie of all time.

Screen Shot 2013-11-25 at 10.34.34 AMIn addition to “Avengers: Age of Ultron,” Marvel Studios will release a slate of films based on the Marvel characters including “Captain America: The Winter Soldier” on April 4, 2014; “Guardians of the Galaxy” on August 1, 2014; and “Ant-Man” on July 31, 2015.

In The Avengers: Age of Ultron, the superheroes reassemble to fight Ultron, a sentient robot who has become one of humanity’s biggest threats since escaping from its creator, Dr. Hank Pym. The original Avengers cast will be back, along with James Spader as Ultron.