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.

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"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.