Colin Meloy, frontman of The Decemberists and already a popular children's author, is now writing a novel for adults.

Meloy's book, which has the working title "Cascadia," is scheduled for 2025 (in the spring, not in December), G.P. Putnam’s Sons announced Thursday.

"Cascadia" features a protagonist named Barnaby Chambers, who sells discarded baby membrane tissue and is otherwise contending with artificial intelligence, climate change and falling birth rates.

ROB LOWE'S LIFE IS FULL OF ‘LOVE, FAMILY, GOD’ AS HE CELEBRATES 33 YEARS OF SOBRIETY

Colin Meloy

Colin Meloy of The Decemberists performs on Nov. 10, 2018, in Leeds, England.  (Andrew Benge/Redferns)

CLICK HERE TO GET THE FOX NEWS APP

"This story, the story of Barnaby Chambers in a near-future Oregon wrecked by climate crises and hypercapitalism, is one I’ve wanted to tell for a very long time now," Meloy said in a statement.

The Decemberists are known for such albums as "The Hazards of Love" and "The King Is Dead," and received a best rock song Grammy nomination in 2011 for "Down By the Water."

Meloy's previous books include the children's stories "Wildwood" and "Under Wildwood," both illustrated by his wife, Carson Ellis.