Billie Eilish’s third album is “85% done” according to her brother and collaborator Finneas.

During an interview with Mr. Porter, Finneas revealed that while the LP is nearly finished, it was still a “challenging” process.

“I don’t think Billie was particularly sure about how she actually felt about the things we were trying to write about. Making a thing that you feel really connected to – it can really evade you.”

He admitted that he “got a little rusty” at songwriting during their intense tour schedule. “And that was scary,” he said. “It was discouraging to realize that if I take time off, my songwriting muscle atrophies. I had to get back in shape.”

Finneas and Billie Eilish’s most recent collaboration “What Was I Made For?” for Barbie is nominated for five Grammys and a Golden Globe.