Niki Caro is a filmmaking chameleon. The New Zealand director can go from folklorish historical drama "Whale Rider" to the Disney sports movie "McFarland, USA" (which, if you haven't seen, is totally awesome). Before she embarks on what can easily be considered her most anticipated movie, a live-action remake of Disney's animated classic "Mulan" (the one without musical numbers), she has another type of movie to release -- a harrowing, true life World War II story called "The Zookeeper's Wife."

In "The Zookeeper's Wife," Jessica Chastain plays the titular character, Antonina Żabińska, a woman in Poland who, after the Nazis invade, uses her beloved Warsaw zoo to hide Jewish refugees right underneath the Germans' noses. (Her husband, Jan, became a full-on freedom fighter.) It's not the easiest movie to watch (there was a woman in my screening who can only be described as wailing) but it is incredibly compelling, anchored by a typically wonderful performance by Chastain.

It's one of those stories from the war that you never hear about (unless you'd read the best-selling book the movie is based on), and so just experiencing it is incredibly edifying and unique. But be warned: you'll probably wail, too.

I got a chance to chat with Caro on the phone about what drew her to the movie, balancing the horrors of the war with the audience's threshold for misery, and how many animals Jessica Chastain held during the course of production.

Moviefone: How did you come upon this project? Were you a fan of the book?

Niki Caro: It came upon me, as a script. Like just about everybody in the world I had never heard of it and I couldn't believe it. As a filmmaker I couldn't believe that it hadn't been made into a movie before and totally thrilled that I was the one who was going to be able to do it.

What about the story spoke to you?

It was the Żabińskas radical humanity that spoke to me, first and foremost. It was the fact that this Polish Christian couple did what they did for no other reason than it was the right thing to do, spoke to a kind of humanity and decency that was really very inspiring to me.

It seems like a good movie to come out now.

No sh*t. Seven years ago, when I began, it was a historical drama. And now it's totally contemporary. That horrifies me but it just means that the movie is very relevant for now.

Jessica Chastain was on the movie nearly as long. What was that collaboration like?

Beautiful. I love her. She's so deeply impressive as a human being and kind of a peerless actress. It was nothing but a joy to collaborate with her on a movie that is so profoundly and consciously female. It was a great experience.

[I tell her the story about the wailing woman.] Was there a trial-and-error thing in terms of how much you were going to explicitly show versus how much you were going to hold back?

No. I think filmmaking, for me, is very instinctive. I hate sentimentality so I tend to be really unsentimental, sometimes at my peril. I think when you're unsentimental and truthful that is where the material can be very, very moving and emotional, when it doesn't manipulate the audience but opens the door for the audience to connect and feel. That's when you get people howling in the cinema. I think that's where you can create stories that can stay with people, so that it's not a movie that is consumed and forgotten but one that I hope stays with people and I hope stands the test of time.

Now, a really serious question: How many animals did Jessica Chastain hold in this movie?

Somebody suggested that we could make a calendar of her holding animals. I said that I actually have all of those images in my phone. I could literally make a calendar of Jessica Chastain cuddling the animals from "The Zookeeper's Wife." There were many. But she loved to cuddle them and they loved her right back. She was very respectful of all the animals, of waiting for them to allow her into their space. She's a genuine animal whisperer, and I say that with no cynicism whatsoever. She has this otherworldly connection with these creatures, which is very rare.

It was just exciting to see so many real animals in a movie.

Yeah, it's beautiful, and the connection between them is genuine. It's a very unusual and special part of this story. She's very connected to Antonina in that way. They're very similar.

Did you do additional research for the story or was it all taken from the source material?

We spent time at the Warsaw Zoo, we spent time with Antonina's daughter Theresa, who is the little blonde girl in the movie, all grown up. In fact, she's in our movie, in the cocktail party scene. In fact, Jessica serves her some snacks. And, of course, you know all the deep research that we did into the Warsaw ghetto and all of those incredibly intense details of that time in history.

"The Zookeeper's Wife" is out everywhere this Friday.