The backstory of Steven Rowley’s new nearly seven-figure book deal with Simon & Schuster is the stuff of publishing fairy tales. The struggling screenwriter initially thought he would self-publish his debut novel, but now S&S is taking the book to next week’s London Book Fair, where the publisher hopes it will emerge as one of the big books of the show.

Karyn Marcus, at S&S, acquired world rights to Lily and the Octopus under unusual circumstances. The manuscript landed in her inbox through a former colleague, Molly Lindley, who is now working as a freelance editor. Although Marcus has received dozens of manuscripts through unorthodox channels, she admitted that the un-agented projects that have come her way have all been “not ready to be read.” But Rowley’s book came with a strong plug from Lindley, who said it was the best thing she had edited all year.

Rowley, who is 43, has sold a few screenplays but has never had a project produced. He wrote the novel more for personal than professional reasons; he started it while he was coping with the loss of a longtime partner. Lindley told Marcus that Rowley was, at most, hoping that a small publisher would take it on.

Based on Lindley’s recommendation, Marcus dove into the manuscript. Once done, she said, “I didn’t literally pinch myself... but I was in a state of disbelief.” Marcus was stunned by the quality of the novel, which employs elements of magical realism. It follows a lost young writer who finds solace in his relationship with his aging dachshund, Lily. When the dog, who begins to talk to him, finds that a small octopus has affixed itself to her head, the odd turn of events forces the narrator to “come face to face with true loss,” according to S&S.

The book, which S&S is comparing to uplifting literary bestsellers with an animal bent such as The Life of Pi and The Art of Racing in the Rain, was a revelation for Marcus. “I have received un-agented manuscripts that people have asked me to read, but I’ve never bought anything un-agented,” she said, adding that Rowley’s book is the “kind of book you always hope to be able to put an offer on.” Calling it “wholly original,” she noted that S&S believes it has the potential of those two aforementioned hits and “will resonate with a lot of people.”

After completing the book, Marcus told Rowley to expand his goals for it and that, even if S&S didn’t ultimately take the book, he should be thinking bigger than self-publishing. In their next conversation, Marcus told Rowley that S&S wanted to buy the novel but that he should hire an agent to represent his interests. (Rowley is now represented by Rob Weisbach of Rob Weisbach Creative Management.)

Rowley, who Marcus said is still a bit overwhelmed by the whirlwind acquisition, has just begun to think of himself as a writer. In an email to his new editor, Rowley said that when asked about his profession, he’d previously responded that he was a paralegal, “and also a writer.” That’s now changed. As he wrote to Marcus, “I am a writer first and foremost, no matter what else I do.”