Casting calls have revealed a lot about upcoming shows and movies. The recent leak of a 'Game of Thrones' audition tape has led to speculations about the storyline involving Tyrion Lannister and a new Red Priestess.

[WARNING, POSSIBLE SPOILERS AHEAD]

A casting call for the highly awaited 'Avengers: Infinity War - Part I' has recently revealed the identity of a new villain and the return of a beloved character.

Acting Auditions has just published a casting call for the movie, asking for principal actors. An excerpt of the cast call reads as follows:

"Auditions are set to get underway for the Marvel Studios feature film 'Avengers: Infinity War - Part I' new lead and supporting roles. The auditions for new lead and supporting roles will be taking place in Los Angeles, CA. The film is the first in a two-part sequel in which Thanos plays a major role, along with the Magus. Adam Warlock's bad side, the Magus, separates from his body and assembles the Infinity Gauntlet."

The Magus has been a counterpart to Thanos in the comic book. The casting call not only reveals that the two villains will be working together, but it also opens up the possibility of Adam Warlock making an appearance in 'Infinity War.'

The casting call continues to enumerate the lead actors of the film.

"Starring in "Avengers: Infinity War - Part I' is two-time Academy Award nominee Robert Downey Jr. as Tony Stark, BAFTA Award nominee Tom Hiddleston as Loki, Academy Award nominee Josh Brolin as Thanos, BAFTA Award nominee Chris Hemsworth as Thor, and People's Choice Award winner Chris Evans as Captain America."

It looks like Loki will return after his absence in 'Avengers: Age of Ultron.' Tom Hiddleston was previously confirmed to appear in the film by former costar Idris Elba, but director Joss Whedon had explained that Elba "misspoke" about the casting.

'Avengers: Infinity War - Part I' is scheduled for release on May 4, 2018.