The cast for “Thor” is starting to fall into place this week, with Tom Hiddleston tapped to play Loki, the mischievous foe of the god of thunder.

Announcement of the up-and-coming British thesp follows Marvel Studios’ recent decision to make Chris Hemsworth, currently seen in “Star Trek,” its hammer-wielding superhero.

Nicknamed the god of lies and mischief, Loki uses his talents at sorcery to try to kill Thor, his more powerful brother, whom he resents.

Kenneth Branagh, who is prepping to direct “Thor” for a May 20, 2011, release, already had a relationship with Hiddleston, having co-starred with the actor in the BBC miniseries “Wallander.” The two were in a London stage production of “Ivanov.” Hiddleston also played Winston Churchill’s son in HBO’s “The Gathering Storm.”

Mark Protosevich, Ashley Miller and Zak Stentz penned the script for “Thor.”

After hiring bigger names for “Iron Man” and “The Incredible Hulk,” Marvel’s turned to virtual unknowns for “Thor,” a superhero based around Norse mythology.

Marvel says the idea is to help auds ease into the property and get to know the character; an established actor would be a distraction. Successful launch of “Thor” is key for Marvel, considering the character is part of the Avengers (also made up of Iron Man, the Incredible Hulk and Captain America), whom the company wants to team up in a pic planned for 2012.