It's truer than true — a posthumous Dr. Seuss book is being released in September, 28 years after the author's death, Random House Children's Books announced Thursday. According to the press release, the book is about "creating and experiencing art."

"Dr. Seuss' Horse Museum" will be released on September 3, 2019, with a first printing of 250,000 copies. The original manuscript was discovered in the home of the late author, whose real name was Theodor Seuss Geisel, along with the 2015 bestseller "What Pet Should I Get?"

The book is about a friendly horse who takes a group of students on a tour of an art museum. "Artists and non-artists alike will appreciate the timeless theme in Dr. Seuss' Horse Museum that there is no one right way to interpret the beauty we encounter every day," the press release says.

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The unfinished manuscript has since been finished by acclaimed illustrator Andrew Joyner, who took inspiration from Seuss' original sketches to complete the book. The illustrations accompany photographic reproductions of famous horse artwork by Pablo Picasso, Alexander Calder, Jackson Pollock and many other artists. Dr. Seuss characters from other stories — including the Cat in the Hat, the Grinch and Horton the Elephant — also make cameos throughout.

This image released by Random House Children's Books shows the cover for "Dr. Seuss's Horse Museum." Random House Children's Books via AP

The Publisher's Note at the end of the book will reveal insights into the discovery of the manuscript and sketches, Seuss' love of modern art, Joyner's creative process and information about the artists.

"This new book will not only entertain as only Dr. Seuss can, but is sure to inspire conversations about the countless ways we each view the world around us, Susan Brandt, Dr. Seuss Enterprises, L.P. said. "We happily expect that many children will be asking, 'What do YOU see?' after sitting with this latest creation by Dr. Seuss."

The announcement of the new Seuss book comes on the heels of Netflix's tease of a 13-episode animated adaptation of Seuss' beloved book, "Green Eggs and Ham." The series, produced by Ellen DeGeneres, will debut this fall — and it features the voices of Adam Devine and Michael Douglas, with cameos by a handful of other stars.

In the show, unlikely friends Sam I Am and Guy Am I go on an adventure to try to save an endangered animal called a "Chickeraffe" from a zoo, learning about hope, friendship and of course, green eggs and ham along the way.