[1] Following her father's death in 1924, the income from Caspary's writing was at times barely sufficient to support herself and her mother, and during the Great Depression she became interested in socialist causes.

Caspary joined the Communist Party under an alias, but not being totally committed and at odds with its code of secrecy, she claimed to have confined her activities to fund-raising and hosting meetings.

[2] Caspary visited Russia in an attempt to confirm her beliefs, but became disillusioned and wished to resign from the Party, although she continued to contribute money and support similar causes.

She eventually married her lover and writing collaborator of six years, Isidor "Igee" Goldsmith; but despite this being a successful partnership, her Communist connections later led to her being "graylisted", temporarily yet significantly affecting their offers of work and income.

[1] After her graduation from high school in 1917, her father enrolled her in a six-month course in a business college, and by January 1918, Caspary found herself working as a stenographer.

This job provided free tickets to theater shows, concerts, and nightclubs and introduced her to a wide circle of press agents and celebrities.

Moving back to Chicago, she co-wrote the play version Blind Mice with Winifred Lenihan, which featured an all-female cast and formed the basis for the 1931 film Working Girls.

[2] Thicker than Water received good reviews, but by then even her publisher Liveright was feeling the pangs of the Great Depression and Caspary was again nearly broke.

By this point in the Depression many intellectuals were flirting with Socialist causes, and Ornitz tried to interest Caspary by giving her The Communist Manifesto, the Daily Worker and other materials.

Upon returning to Greenwich Village, Caspary was invited to join the Communist party by a very prominent playwright, and did so, though under the alias of "Lucy Sheridan".

Caspary found the Party's code of secrecy to be contrary to her search for truth and questioning of values, which had led her to join in the first place.

[2] Though she claimed to never actively recruit anyone, she admitted performing Party chores such as fund-raising and hosting the fortnightly Confidences Club meetings at her home, which were mostly for socializing.

In April 1939, Caspary used the profits of a Hollywood story sale to travel to Russia to "see how people lived" in what the Daily Worker had described as a paradise.

During her trip across Europe she was nearly persuaded from guilt to marry an Austrian Jew in order to get him to the United States, but due to a slowness in paperwork she was saved that fate.

During this time Caspary started tinkering with a murder mystery, but instead of producing an original story for the screen she was encouraged to turn it into a novel.

When the United States declared war on Germany and Japan in early December, that story was canceled, and Caspary asked to be laid off and returned happily to her murder mystery.

[2] Herbert Mayes, editor at Good Housekeeping had conceived the idea of Murder at the Stork Club, and he chose Caspary to write the story.

The English Harper's Bazaar also wanted Murder at the Stork Club, and its editor Ben McPeake, like Mayes in New York continually checked on the story's progress.

They were terribly happy in post-war Hollywood, jobs were plentiful, salaries high and the parties seemed endless – Caspary's newfound fame brought her into contact with anyone who was anyone.

Her stories improved by Igee's contribution were selling at inflated prices, and her salary rose due to high demand for her work and her limited availability.

While in Europe finalizing the divorce, Igee traveled to visit his grown son in Switzerland and, while there, bought Caspary a small chalet in nearby Annecy.

Many small production companies went bankrupt as a result of United Artists' troubles – Caspary could not afford to, as she would have lost future royalties for works she had written and any payments for reprints of her books.

The couple were preparing to leave for Europe, as Igee was negotiating a French remake of Three Husbands, when MGM abruptly and illegally questioned Caspary regarding her Communist links.

Since Caspary had left the Party before she came to Hollywood, she told the truth about which committees she attended and the initiatives she had worked on, but the one thing they never asked was if she had ever been a member.

It was while working in Austria on the musical adaptation of Daddy Long Legs, Caspary learned she had been added to the gray list and told to abandon the project.

Years later, Caspary remembered George Cukor's Les Girls with Gene Kelly and Mitzi Gaynor as her most enjoyable studio experience.

The novel Evvie, about two emancipated girls in the 1920s and heavily based on her own experiences,[1] was begun in London, continued in New York, finished in Beverly Hills, and proofed in Paris.

She reworked an idea that she had begun in Austria and that had been rejected in London, altering it to fit American situations, and to her shock 20th Century Fox offered $150,000 for it.

[2] Caspary returned to New York after Igee's death, where she published eight more books, including The Rosecrest Cell, a study of a group of frustrated amateur Communists; and the memoir The Secrets of Grown-ups.

In her 18 published novels, 10 screenplays and four stage plays, Caspary's main theme, whether in a murder mystery, drama or musical comedy, was the working woman and her right to lead her own life, to be independent.