The 34-year-old actress and 38-year-old actor will star as Hope Pym and Darren Cross, respectively. Lilly is known for her role as Kate Austen on Lost and the elf Tauriel in The Hobbit movies, while Stoll appeared as U.S. Representative Peter Russo on the first season of House of Cards and currently portrays Dr. Ephraim Goodweather on The Strain.
The actors join Michael Douglas as Dr. Henry "Hank" Pym and Paul Rudd as Scott Lang. Pym is an entomologist and physicist who develops the size-shifting substance and becomes the superhero Ant-Man in the 1960s. He eventually passes the mantle to reformed thief and electronics expert Lang.
In the Marvel comics, Hope Pym is Hank's daughter with Janet van Dyne, aka the Wasp, and duplicates her mother's size manipulation and bio-electric powers to become the Red Queen. Darren Cross is the head of Cross Technological Enterprises, who obtains some Pym particles to become the villain Yellowjacket.
Ant-Man is directed by Peyton Reed and produced by Marvel President Kevin Feige, and co-stars Michael Pena and David Dastmalchian in undisclosed roles. The movie is scheduled for release July 17, 2015.