No chemistry read necessary for these witches, says director Jon M. Chu.

But somehow Grande and Erivo never actually read together despite both landing the coveted roles.

They didn’t meet until just a few hours before their casting announcement was to go out.

Wicked - Official Trailer Ariana Grande and Cynthia Erivo

Ariana Grande and Cynthia Erivo in ‘Wicked’.Universal Pictures

The duo came together at Chu’s house in the run-up to that moment.

“I didn’t know that they would work.

I didn’t know if they would like each other.

Cynthia Erivo is Elphaba and Ariana Grande is Glinda in WICKED

Cynthia Erivo’s Elphaba and Ariana Grande’s Glinda arrive in the Emerald City in ‘Wicked’.Giles Keyte/Universal Pictures

“So I trusted that that alchemy would work here, and it worked in spades.”

“They came to my house to meet for the first time,” he details.

They just went up there and started singing.

At that moment, their voices intertwined, and I knew it was right.”

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Anyone who watched Grande and Erivo in interviews can instantly see that alchemy that Chu mentions.

Wickedpremiered on Broadway in 2003.

The show went on to earn 10 Tony Award nominations in 2004, including one for Best Musical.

The adaptation also featuresJeff Goldblum,Michelle Yeoh,Jonathan Bailey,Bowen Yang, and Marissa Bode.

The film will be split into two parts, and the first half flies into theaters this weekend.