Rita Vandemeyer

In the novel The Secret Adversary, Mrs Marguerite “Rita” Vandemeyer was a woman connected with “Mr Brown”. She was one of the few people who knows his true identity. Mrs Vandemeyer was onboard RMS Lusitania when it got torpedoed, and saw Danvers and Jane Finn speaking.

Tuppence took employment as a maid with Mrs Vandemeyer.

Although Mrs Vandemeyer was "no longer in her first youth", and her beauty was "hardened and coarsened", in her youth she "must have been dazzling". Her hair was pale gold, "owing a slight assistance to art". Her eyes were "of a piercing electric blue", and seemed to "possess a faculty of boring into the very soul of the person she was looking at".

Mrs Vandemeyer had "swaying grace" and an almost "ethereal beauty" about her face, but one "felt instinctively the presence of something hard and menacing", which was expressed in the tones of her voice and the "gimlet-like" quality of her eyes.

Mrs Vandemeyer saw Sir James Peel Edgerton socially, and although Boris Ivanovitch urged her to stop seeing him, she refused. When Boris asked if she thought she could deceive him, she said that it would amuse her to try, and that besides that, he was extremely rich, and she valued money.

Mrs Vandemeyer later threatened Tuppence with a pistol, after finding out that she was a spy. However, Tuppence gained the upper hand, and offered Mrs Vandemeyer a hundred thousand pounds in exchange for information. Mrs Vandemeyer said that she could find out where Jane Finn wa, and that she would ask Boris about Tommy's whereabouts. She also agreed to tell Tuppence the identity of Mr Brown.

Before Mrs Vandemeyer could reveal the identity of Mr Brown, she was startled by the sudden appearance of Sir James and Julius Hersheimmer. She fainted, and later died from an overdose of a sleeping draught.

Towards the end of the novel, Jane Finn reveals that Mrs Vandemeyer had been quite near her on the Lusitania when Danvers gave her the packet containing the draft treaty. After that, Mrs Vandemeyer had been very keen to look after her. After Jane was abducted by the gang, Mrs Vandemeyer told her that she was her niece.