For certain corners of the internet, a 1976 paperback edition of Madeleine L’Engle’s novel A Wrinkle in Time has been the source of an enduring mystery: Who was the artist behind its spooky, glowing-green cover art?

After a few hours of research, the podcast host Amory Sivertson thought she had found the answer. She had emailed a gallery to ask if an artist it represented had made the cover and a worker said yes.

She was wrong: A day later, the gallery worker apologized for the miscommunication. It would be two months, hundreds of emails and a number of awkward cold calls before she actually found the correct name.

The mystery cover art shows a strapping centaur with delicate wings flying above a menacing green face with bright red eyes. Craggy mountains and fluffy dark clouds surround the haunting figures. The website Book Riot called the art “nightmare fuel.” The artist’s name isn’t mentioned anywhere in the book.

…After an exhaustive search, In late June, she was given the correct name: Richard Bober. Mr. Bober died last year, but Ms. Sivertson was able to speak with his relatives in early July, and she said they found proof that he had made the cover art.