The director of "Thor: Ragnarok" teases on social media a possible return of Natalie Portman's Jane Foster. Meanwhile, could Hela (Cate Blanchett) be working with Thanos (Josh Brolin)?

"Thor: Ragnarok" director Taika Waititi shared a photo on Twitter that teases the return of Jane Foster in the film. On the director's post was a before and after side-by-side of Portman holding similar items. Other than the age difference, another noticeable thing is that Portman appears to be pregnant in the "after" photo.

Waititi captions the post, "Heed the signs. #Ragnarok."

This sparked speculations that Portman will be reprising her role as Jane Foster in "Thor: Ragnarok."

However, Marvel Studios president Kevin Feige already confirmed previously that Portman will not be appearing in the sequel in an interview with Empire Film.

Feige explains that there are "many reasons" why Foster will not be part of the storyline, even though a few parts of the film will take place on Earth. He also adds that some of the reasons of Foster's no-return will appear in the film for the viewers to see.

Meanwhile, there are speculations that Hela is working with Thanos in "Thor: Ragnarok."

In an interview with Entertainment Weekly, Blanchett explains that Hela has "been locked away for millennia, getting more and more cross, and then, with a mistake, she get unleashed."

Many speculate that this mistake involves Thanos, though there is no confirmation yet if and how the big bad is responsible for Hela's freedom.

One reason to believe that Hela is working with Thanos is the possibility of her being in possession of the Infinity Stone, which is what the big bad is aiming to collect. Another speculation is that Thanos has a "bad romance" with Hela, and that the two are working together in taking over the whole universe.

"Thor: Ragnarok" is slated to premiere on Nov. 3.