Hugh Hornbeam is a non-canonical character created for the ITV 2006 adaptation of Sleeping Murder. He is an employee in the London office of Vanstone International, the company headed by Charles Vanstone who, in this adaptation, is the fiancé of Gwenda Reed. Because Vanstone needs to remain in India for business reasons, he assigns Hornbeam to look after Gwenda when she arrives in England and help her with the preparations for her wedding. Hornbeam replaces Giles Reed in the original novel as the person who accompanies Gwenda throughout most of the investigations in the episode. Hugh Hornbeam is portrayed by Aidan McArdle.
At the time of the events in the episode, Hornbeam had been in Vanstone International for seven years. He joined the company at the end of the Second World War. He was originally a geologist by training but with his mother left alone and two much younger brothers, Hugh decided that being a geologist would not support his family and so joined the world of commerce.
When Gwenda started having strange memories about what happened in Hillside, the house she bought, Vanstone instructed Hornbeam to bring in an investigator, or "someone who'll take her seriously". Hornbeam called Miss Marple. Apparently he knows Miss Marple personally although what relation he is of hers is never made clear.
At the end of the episode, Miss Marple encourages Hornbeam to propose to Gwenda. He does so and she accepts.