She was my only choice, said Nair of her dear family friend.

The two women go way back.

Nair also wrote a letter on Nyongos behalf when she was applying for her U.S. visa.

Queen of Katwe

Credit: Edward Echwalu

Shes like a daughter, she says.

Despite knowing her so well, Nair was still impressed by Nyongos work ethic.

There was a consistency in her emotion.

Nothing could distract her.

That leads to a really authentic, truthful space, says Nair.

Shes not striving to convey something, shes already embodying it.

For Nyongo, the physical attributes of a specific character serve as an entry point to unlocking their uniqueness.

To play Harriet, she needed to understand how her body worked.

Harriets lifestyle is way more earthen then mine, she says.

The buying and selling of corn.

They do sit very low on the ground and they have very, very flexible hips.

I did a lot of yoga to get my hips to relax like hers.

That dedication wasnt lost on David Oyelowo (Selma), who plays Phionas chess coach and mentor.

God is in the details of that woman.

This is a true-blue actress who did everything she could to go toward her character.

Queen of Katweopens on Sept. 23.