Drew talked with People.com about meeting Toni and about filming together on Miss You Already.

When two actresses meet each other for the first time before filming, there’s no way to predict what the chemistry will be like.

But in Miss You Already, a story about the complexity of female friendship, chemistry was the most important factor for the film. Luckily for Drew Barrymore and Toni Collette, they hit it off right away.

“We unzipped and jumped right in,” Barrymore, 40, tells PEOPLE at the Toronto International Film Festival. “We really got along and we liked each other. We had the electric connection and you can’t fake it. You hope for it, but you don’t know what it’s going to be like when you show up.

Collette, 42, noted that the two women had mutual friends but that they had never really gotten to know each other before taking on the roles. As soon as they began working, though, forming a friendship was “instant and easy,” she said.

Miss You Already tells the story of two lifelong best friends at different crossroads in their lives. Their friendship is put to the test when one starts a family and the other is diagnosed with cancer.

“This [story] is such a celebration of life,” Barrymore says. “You’re not always perfect and weepy. You’re selfish and you’re angry and it’s humorous and you make each other laugh – you’re connected, you’re distant. Lifelong friendship takes so many extraordinary things – it’s birth, it’s death, and that’s what’s all in this film somehow in the most unheavy-handed way.”

Miss You Already made its debut at the film festival on Saturday. It will hit theaters everywhere on Nov. 6.