The working title for the next Marvel Avengers movie, Avengers: Infinity War, has been revealed by Production Weekly.

Avengers: infinity War is operasting under the working title “Mary Lou” during production. This follows Marvel’s The Avengers, which operated under the working title “Group Hug,” and Avengers: Age of Ultron, which operated under the working title “After Party.”

Avengers: Infinity War is directed by Anthony and Joe Russo, from a screenplay by Christopher Markus & Stephen McFeely.

Avengers: Infinity War still does not have a firm plot synopsis, but is expected to bring together most of the characters so far introduced into the Marvel Cinematic Universe. They will face down the threat of Thanos, who has been lurking and scheming in the background since at least as far back as The Avengers.

Avengers: Infinity War is expected to feature Marvel Studios heroes including Iron Mna (Robert Downey Jr.), Captain America (Chris Evans), Thor (Chris Hemsworth), Doctor Strange (Benedict Cumberbatch), Star-Lord (Chris Pratt) and the Guardians of the Galaxy, and more.

The Avengers is the flagship film in Marvel Studios franchise. Marvel’s The Avengers earned $1.52 billion at the worldwide box office. Avengers: Age of Ultron earned $1.4 billion worldwide. Both films were directed by Joss Whedon.

The Russo Bros. have directed two Captain Americamovies for Marvel Studios. Captain America: The Winter Soldier earned $715 worldwide. Captain America: Civil War earned $1.15 billion.

Avengers: Infinity War is scheduled for release on May 4, 2018.