A 100-year-old story written by Beatrix Potter is finally going to see the light of day. The story will be published in September, complete with illustrations by Quentin Blake.

The story, titled The Tale of Kitty-In-Boots, was written in 1914, reports The Guardian. It was discovered 100 years later in a letter Potter sent to her publisher that was found at the Victoria And Albert archive in London by publisher Jo Hanks.

As Reuters notes, Hanks discovered a biography of Potter that mentioned the story, which led her to a search for the letters. In addition to the manuscripts, she also found a rough sketch of Kitty-In-Boots.

The story also features many other familiar Potter-created characters, including an older version of Peter Rabbit.

Potter wrote in other letters that she had hoped to finish the story, but got delayed by other events, like the start of World War I, her marriage and illnesses. She died in 1943 and the story was never finished.

Blake was asked to illustrate the story. He is one of Britain’s best-known illustrators, thanks to his work on Roald Dahl’s books.

“I liked the story immediately – it’s full of incident and mischief and character – and I was fascinated to think that I was being asked to draw pictures for it,” Blake told the Guardian. “I have a strange feeling that it might have been waiting for me.”

Readers will meet Kitty-In-Boots in September, when it is published by Penguin Random House.