In the novel The Sittaford Mystery, Emily Trefusis is an amateur sleuth. She is the fiancée of James Pearson.
Mr Rycroft asks Emily if the name Trefusis is a Cornish name. She answers that it is, and that her father was from Cornwall. He mother was Scottish.
Portrayals
In ITV's 2006 adaptation of the novel, Emily Trefusis is portrayed by Zoe Telford. Here she is also engaged to James Pearson and undertakes investigations to clear his name when he is suspected of murdering his guardian Clive Trevelyan. However her backstory is slightly different. Here her father is named as "Max Trefusis", described in the social column of a newspaper as a "colourful financier". According to journalist Charles Burnaby, her father had been involved in all sorts of scandals, including black market activities during the Second World War, insurance fraud and some "extraordinary party he threw in Biarritz with the Windsors and the gendarmes". Early in the show, Burnaby threatened to publish all this unless Emily helped him get an interview with Captain Trevelyan. Emily was also once engaged to Raymond West but broke off the engagement in favour of James Pearson. Raymond was the one who introduced James to Emily.