Paul McCartney is preparing the sequel to his popular 2019 illustrated children’s book, Hey Grandude!.

Announced on Friday, Grandude’s Green Submarine will be published in the United States via Random House Books for Young Readers on September 2nd. Similar to Hey Grandude!, the book will feature illustrations from artist Kathryn Durst. An audio version of the children’s book will also be available to purchase on CD.

The book’s synopsis on the Penguin website reads, “Join Grandude and his grandchildren as they set off on an exciting adventure, this time in a very special, magical submarine. They fly through the sky, ride a river through a jungle and go deep under the ocean, as they search for their grandmother – Nandude – another adventurer who loves making music!”

“I’m really happy with how ‘HEY GRANDUDE!’ was received, as this was a very personal story for me, celebrating Grandudes everywhere and their relationships and adventures with their grandchildren,” McCartney also added in a press statement,  “I love that it has become a book read to grandkids at bedtime all around the world. I always said if people liked the first book and there was an appetite for more, I would write some further adventures for Grandude—so he’s back and this time with his special invention, Grandude’s green submarine!”

Related: Netflix To Produce Animated Film Based On Paul McCartney-Penned Children’s Book, ‘High In The Clouds’

Click here to pre-order a copy of the book ahead of its September release.

Earlier this month McCartney announced a forthcoming covers album featuring new recordings of songs from his 2020 McCartney III solo album as performed by St. Vincent, Phoebe Bridgers, Damon Albarn (Gorillaz), Beck, Khruangbin, Ed O’Brien (Radiohead), Blood Orange, Anderson .Paak, and more.

McCartney will also release a 960-page semi-autobiographical book, The Lyrics: 1956 to the Present, which will recount his career in showbusiness along with his personal journey through the lyrics of 154 songs written over the span of his life. The book is due out on November 2nd.