Screenwriting

Mathis was determined to become a screenwriter and, accompanied with her mother, she moved to New York City, where she studied writing and went to the movies in the evenings.^[6] She entered a screenwriting competition; but despite not winning, her entry was so impressive it did bring job offers.

Her first script, House of Tears, would be directed by Edwin Carewe in 1915 and led to a contract in 1918 with Metro studios, later to be merged into MGM. As one of the first screenwriters to include details such as stage directions and physical settings in her work, Mathis saw scenarios as a way to make movies into more of an art form. Much of the standard screenwriting styles can be attributed to her. Mathis later credited her success to a strong concentration on plot and theme: "No story that did not possess a theme has ever really lived.... Occasionally one may make money and perhaps be popular for a time. But in the end it dies."^[6]

By 1919 Mathis and her mother had moved to Hollywood. After only a year of screenwriting, she had advanced to the head of Metro's scenario department.^[7] She was one of the first heads of any film department and the only female executive at Metro.^[8]

During her early years, she had a close association with silent star Alla Nazimova. Their films together can be said to be marked by over-sentimentality; what little praise these films received was due to Nazimova's acting rather the conventional romantic stories.^[6]

The Four Horsemen of the Apocalypse

In 1921, Richard Rowland, the head of Metro, paid $20,000 and 10% of the gross earning for Vicente Blasco Ibáñez's novel The Four Horseman of the Apocalypse.^[9] The epic bestseller had been considered unadaptable by every major studio but Rowland handed the book to Mathis for adaptation and was so impressed with her screenplay that he asked her input on director and star. Mathis had seen Rudolph Valentino in a bit part in Eyes of Youth, and she exerted her influence to cast Valentino. Studio heads resisted hiring an unknown actor for a lead role.^[10] Despite her many other accomplishments, this "discovery" would grow to be her best-known act. For the same movie she also insisted the studio hire Rex Ingram as director.^[7]

The Four Horsemen of the Apocalypse was one of the first films with an anti-war theme. Mathis also injected some early depictions of alternative lifestyles; it featured a scene with German officers coming down the stairs in drag. Of the scene, Mathis later told the Los Angeles Times: "I had the German officers coming down the stairs with women's clothing on. To hundreds of people that meant no more than a masquerade party. To those who have lived and read, and who understand life, that scene stood out as one of the most terrific things in the picture."^[3]

Executive

Mathis' position with Metro was called by the Los Angeles Times, "The Most Responsible Job ever Held by A Woman".^[15] She was arguably one of the most powerful women in Hollywood, even said to be almost as powerful as Mary Pickford. Mathis had influence over casting, choice of director and many other aspects of production.^[7] Her strength lay in careful preparation of the shooting script along with the director, cutting out waste in production while at the same time sharpening narrative continuity.^[16]

After she had spent seven years at Metro, Famous Players–Lasky was able to lure her away with the promise that she could continue to write for her protégé Valentino. When Valentino moved to Goldwyn Pictures, she did as well, this time gaining sovereign control.

Greed

Mathis continued to survive in Hollywood despite being involved in two of the greatest financial fiascoes of the 1920s. When Erich von Stroheim presented Goldwyn Pictures with his masterpiece Greed (1924), following Frank Norris's novel McTeague very closely, it was 42 reels and 10 hours long. Stroheim himself realized the original version was far too long, so he reduced it to 24 reels (6 hours), hoping the film could be screened with intermissions in two successive evenings. But Goldwyn executives demanded further cuts. Stroheim allowed his close friend Rex Ingram to reduce it to 18 reels (4½ hours).^[16]

However, in the middle of production, Goldwyn had merged with Metro and Louis B. Mayer Pictures to form Metro-Goldwyn-Mayer. MGM took Greed out of Stroheim's hands and gave it to Mathis, with orders to cut it even more, which she assigned to a routine cutter, Joseph W. Farnham. The film was then reduced to 13 reels (2½ hours) long. In the process, many key characters were cut out, resulting in large continuity gaps.^[17]

There is speculation on whether Mathis took part in the actual cutting. However, for contractual reasons, her name was listed in the credits as a writer, and it was she who would be blamed for what Stroheim and his fans would call "tampering with his genius".^[7] In fact, Mathis had worked with Stroheim before and had been fond of his themes, and thus it is thought unlikely she would butcher his film unnecessarily.^[3]

Ben-Hur

For the original production of Ben Hur (1925), Mathis fought the studio over the casting and production for many months. It was her idea to film the $1 million script in Italy; the film would eventually come in just under $4 million. When she arrived the original director Charles Brabin, in his words, refused to let her "interfere". The production troubles were numerous, and due to political troubles engulfing Italy at the time, resulted in disputes and delayed permissions. When the sea battle was filmed near Livorno, Italy, many extras had apparently lied about being able to swim. The first attempt to film the chariot race was on a set in Rome, but there were problems with shadows and the racetrack surface. One of the chariots' wheels came apart and the stuntman driving it was thrown in the air and killed.

MGM inherited the production when it took over control of Goldwyn studios; with the film over budget and getting out of control, the studio halted production and relocated the shoot from Italy to California, under the supervision of Irving Thalberg. All of Brabin's footage was reviewed and considered unusable, and MGM would fire Mathis, Brabin, and stars George Walsh and Gertrude Olmstead; Replacing them with director Fred Niblo, screenwriters Bess Meredyth and Carey Wilson, and stars Ramon Novarro and May McAvoy.^[7]

After her return, First National hired her as editorial director. She also scripted several successful Colleen Moore pictures including Sally, The Desert Flower, and Irene. Mathis remained at First National for two years, but left over limitations and signed with United Artists; with her husband she made one picture for them, The Masked Woman. The Magic Flame (1927) would be her last picture, and one of her best, due in part to Ronald Colman's performance and Henry King's direction.^[6]