Literary mysteries: Books that have been permanently lost

The question: What books have been permanently lost?

Long-lost manuscripts have been popping up left and right lately. New books from Harper Lee and Dr. Seuss, both written decades ago, are hitting shelves in July. But there are some manuscripts out there that may never be found.

Several well-known authors wrote books that have since been lost to time, or in Ernest Hemingway's case, lost to a thief in Paris.

Ernest Hemingway's stolen World War I novel

In Switzerland in 1922, a young Hemingway thought he'd found his big break when an editor asked to see more of his writing. At this point, none of Hemingway's fiction had been published yet, and he was making his way as a fledgling reporter.

Hemingway wrote to his wife Hadley (wife one of four) to bring his work by train from their home in Paris. She dutifully packed up everything Hemingway had written — everything.

At the train station, as the tale goes, she strayed from her luggage for just a moment and when she returned, the suitcase was gone. It was a double blow when Hemingway discovered that Hadley had packed not just the originals of his work, but the carbon copies as well.

The only stories of his that survived were "My Old Man," which he had recently submitted to a publisher, and "Up in Michigan," which he'd shoved in a drawer after Gertrude Stein told him it was unpublishable.

Lost with the suitcase were several stories and the draft of a novel about World War I, which Hemingway never attempted to re-write. According to "The Book of Lost Books," Hemingway was known to claim that the lost suitcase was his reason for divorcing Hadley — a claim that usually came out after a drink or two.

Thomas Hardy's missing first novel

Publishers rejected Hardy's first novel, a manuscript titled "The Poor Man and the Lady." It was the story of just that: a peasant's son, a squire's daughter and a love that could never be. How did it end?

Hardy himself forgot. After the novel was rejected, he went to work on other projects, eventually penning his most famous work "Far from the Madding Crowd." Fifty years later, Hardy discussed his first, unpublished novel with the English poet Edmund Gosse, but many of the details escaped him. He couldn't remember whether the couple ended up together or not.

The manuscript was not found in his papers after his death. Some critics believe portions of the plot were absorbed into his other works.

Sylvia Plath's unfinished work

Sylvia Plath left behind piles of papers when she took her own life in 1963. Her manuscripts and journals became the property of Ted Hughes, her estranged husband.

Correspondence suggests that the pile included a nearly complete new novel to be titled "Double Exposure." Details about the novel are few: A literary critic claimed she saw the outline, and that it had to do with a husband, wife and mistress.

In 1965, Hughes told the Paris Review that he thought Plath's mother had taken it: "Her mother said she saw a whole novel, but I never knew about it. What I was aware of was 60, 70 pages, which disappeared. And to tell you the truth, I always assumed her mother took them all, on one of her visits."

It may have been destroyed. Hughes did admit to burning at least one of Plath's notebooks, which he said was too dark for his children to read.

Correction (May 13, 2015): An earlier version of this story incorrectly listed the year of Sylvia Plath's death. The current version is correct.