The Cause of It AllMovie

Dr. Spencer's wife becomes intensely jealous when she finds, in her husband's coat, a note signed "Mary," which asks him to visit the writer at the Hotel Mum. The woman carries her tale of woe to Attorney Thomas, a family friend. In his effort to make light of the matter, Thomas soothingly places his arm about Mrs. Spencer's shoulder. Dr. Spencer's office is directly across the court. Glancing out of the window, the doctor sees his wife apparently being embraced by Thomas. The attorney consents to accompany Mrs. Spencer to the Mum and meet "Mary." The doctor trails the two. As luck would have it, Mrs. Thomas passes the Mum just as her husband and Mrs. Spencer enter. The doctor and Mrs. Thomas meet and make their way after their other halves, bent on vengeance bent.