Duchess Kate recently did something fun to celebrate the launch of her brand-new book! On Friday, the Duchess of Cambridge's lockdown-inspired photo collection Hold Still: A Portrait of Our Nation in 2020 was released, and she secretly left copies of it around the United Kingdom for people to find!

Duchess Kate becomes a "book fairy" for the day

Duchess Kate and Prince William announced on their newly rebranded Instagram page that they teamed up with organization The Book Fairies for the exciting hunt. "Let the search begin! We've joined @bookfairies_uk for the day to share copies of Hold Still around the UK with you," they wrote, along with video and photos of Kate placing one of the books at Kensington Palace.

They also shared what those who do come across one of the 150 hidden books will see! According to the Duke and Duchess of Cambridge's post, each of these special copies of Hold Still "is adorned with a gold book fairy sticker, gold ribbon, and has a letter from The Duchess tucked inside."

Duchess Kate views archive photos alongside Curator Magda Keaney and Director of the National Portrait Gallery Nick Cullinan on May 7, 2021.

Duchess Kate shares Hold Still contributors have also hidden books

Duchess Kate launched Hold Still in May 2020 in partnership with the National Portrait Gallery with the goal of capturing life in the United Kingdom during lockdown. A year later and the 100 photographs chosen have been collected in a book for the very first time! The royals' statement shared that finalists and judges are hiding books as well, "leaving copies at places that gave them hope during the lockdown."

Friday was a busy day for the Duchess of Cambridge! She also stopped by the National Portrait Gallery— where they revealed the Hold Still exhibit will remain in their collection— and Royal Hospital of London to mark the occasion. As People mentions, the royal stepped out in a vibrant red wool crepe coat designed by Eponine. She also carried a Demellier handbag that matched her beige skirt and heels combo.