Two-time Oscar winner Tom Hanks discusses Emma Thompson’s transformation into P.L. Travers, the author of Mary Poppins, in a new featurette for the upcoming film Saving Mr. Banks. The film tells the story of how Walt Disney secured the rights to Mary Poppins from the stubborn writer.

After promising his daughters that he would make their favorite book into a movie, Disney goes to extreme lengths to appease Travers, a somewhat grumpy woman who fears Hollywood will ruin her beloved story.

In the featurette, which is intercut between scenes from the film and interviews with the cast and crew, Thompson takes on the curmudgeonly author.

“For an actor she was a wonderful case study, requiring so many different shades. She just was so complex,” the two-time Oscar winning actress said. “I’ve never played anyone so fill of contradictions.”

Travers wrote the story of the magical flying nanny, but as the trailer shows, she was very against Disney’s attempts to add chirpy music and prancing actors to the tale.

Hanks, who plays Disney, raves about his co-star’s performance.

“Every time I see her I always wonder, how did she do that? How did she make it look so easy?” Hanks said. He goes on to call Thompson an actress, “who is forever, it seems, at the absolute top of her game.”

The featurette also shows interviews with the film’s director, John Lee Hancock, and starring actor B.J. Novak. Both praise Thompson’s performance as well and with good reason. Variety and The Hollywood Reporter are already talking about the film’s Oscar chances. The race to the Academy Awards is still in its early stages but Thompson, Hanks, Hancock, and the film itself could receive nominations.

Saving Mr. Banks comes to select theaters Dec. 13th, before it’s released everywhere on Dec. 20th.

Check out the new featurette below!