With production scheduled to begin next summer in Australia on Thor: Ragnarok, Marvel has brought in a new writer to work on the screenplay. The Hollywood Reporter reveals that up and coming scribe Stephany Folsom has signed on to rewrite the script for the third Thor adventure. Christopher Yost and Craig Kyle, who wrote both Thor and Thor: The Dark World, previously worked on the Thor: Ragnarok script.

Taika Waititi (What We Do in the Shadows) signed on to direct back in October, and we also reported that Mark Ruffalo is coming back as Hulk. Both Thor and Hulk are said to go on a "cosmic road trip" in this superhero sequel, but no specific plot details have been released thus far. Another report from October teased that the script by Christopher Yost and Craig Kyle is the darkest yet in the Marvel Cinematic Universe.

Taika Waititi, best known for directing light-hearted comedies such as Eagle Vs. Shark and this year's What We Do in the Shadows, is believed to have come aboard to add a comedic balance. The story has been rumored to center on the Norse Apocalypse, but no specific plot details have been given. This new report claims that Hulk and Thor will encounter the Valkyries throughout their journey, and that this movie could introduce the Marvel heroine named Valkyrie, a.k.a. Brunnhilde, as well. Valkyrie was first introduced in the Avengers comics, and she was also connected to The Defenders and Doctor Strange. Valkyrie's most notable enemy was The Enchantress, a character who may also be introduced on the big screen in Thor: Ragnarok.

Related: Thor: Ragnarok Director Recently Met with Marvel, Was It About Guardians 3?

Chris Hemsworth (Thor) and Tom Hiddleston (Loki) are returning for Thor: Ragnarok, with Jaimie Alexander (Lady Sif) expected to return as well. It isn't known if Natalie Portman (Jane Foster), Anthony Hopkins (Odin) and Idris Elba (Heimdall) are coming back to reprise their roles in the sequel. Thor: Ragnarok is scheduled for release on November 3, 2017, just a few months after Guardians of the Galaxy Vol. 2 arrives on May 5, 2017.

Stephany Folsom made the Black List in 2013 for her script 1969: A Space Odyssey or How Kubrick Learned to Stop Worrying and Land on the Moon. The story is an alternate-history telling of a publicist that convinces filmmaker Stanley Kubrickto work with NASA in order to fake the moon landing. She also wrote the script for Disney's The Princess of North Sudan, inspired by the true story of an American man claiming a territory in Africa and proclaiming himself and his family its royal rulers.