Jake Gyllenhaal is celebrating the aunts and uncles of the world.

On Thursday, Feiwel and Friends and Macmillan Children’s Publishing Group announced that it will publish Gyllenhaal’s picture book The Secret Society of Aunts and Uncles on Sept. 5, 2023.

The children’s book, which the 41-year-old Ambulance star cowrote with his longtime writing partner and friend Greta Caruso, follows 10-year-old Leo, his Uncle Mo and “a secret society determined to make their relationship bloom,” a release about the upcoming book reads.

The book will also feature illustrations from Caldecott Medal-winning illustrator Dan Santat.

The Secret Society of Aunts and Uncles is “a madcap, magical adventure into the heart of what it means to have an aunt or uncle—how we learn to keep each other close and how we find love in the simplest things,”.