Sonya is a dancer connected to Martin Cortland's theater production. Martin initially promises her the lead role in the camp performance, but changes his decision after rehearsals because Sheila Winthrop is better suited. Sonya's presence at Robert Curtis's apartment later causes a misunderstanding involving a mislabeled bracelet and leads Sheila to refuse the performance.
A female crew member who survives the initial attacks and the return trip. Consols Colonel Graham during the uncontrolled descent toward Earth, remaining one of the final survivors.
Vera Segert is the unfaithful wife of Gustaf and Eric's lover, whose letters become the basis of a blackmail scheme. She seeks help from Bernard and Christina, deals with Anna over the letters, and attempts to prevent Gustaf from involving the police after Anna is injured.
Helen Robinson is questioned by June Goffe about her whereabouts on the night Edna Bartelli was killed. She is connected to Gus Hoffman as his daughter, and Gus later explains that he killed Edna while trying to protect Helen Robinson's marriage from the consequences of Edna's affair with her husband.
A train passenger carrying a forged inheritance envelope that actually contains secret maps of Turkey. She is fatally wounded in her Ankara hotel, triggering the central espionage plot.
A civilian character representing a personal contact, used to teach agents how to leverage relationships safely without compromising operations.
Arnold's wife, identified in the story as Valerie. Chris is asked to flirt with her as part of an undercover investigation, and she leaves with him, saying she has left her husband. She later tells Arnold that she no longer loves him, while Chris and Joan try to question her about the case.
Osa is Manuel's daughter and a member of the family connected to the ditchdiggers. When the suspicious foreman refuses to hire John because of his well-dressed appearance, she advises him to change his clothes, helping him join the crew. She falls in love with John, feels betrayed when his identity is revealed, and is happy when he tells her Linda has left him to seek a divorce.
Lisa is Ann's sister and develops a romantic interest in John, although John falls in love with Ann. While drunk, Lisa cruelly congratulates Ann on being the one who will watch John deteriorate. Ann slaps her before persuading John not to kill himself.
Osa Massen has 27 screen credits in a career dating back to 1935. Signature works include Rocketship X-M, Outcasts of the City, Million Dollar Weekend. Explore the interactive character relationship maps on each title page to trace how their roles connect across franchises.
