Ros Thorne

 made her first appearance on 3 November 1997. She is portrayed by Clare Grogan.

Storylines
Ros is a Scottish private detective whom Ian Beale hires to trace his two sons, Steven Beale and Peter Beale. Steven and Peter had been taken by their mother, Cindy Beale, following her failed attempt to have Ian killed by a professional hitman in 1996.

Ian and Ros discover that Cindy is residing in Italy and follow her there in November 1997. While hunting for Cindy, Ian and Ros become attracted to each other. They have a brief sexual encounter, though their relationship never progresses into anything serious as Ian is preoccupied with his children. After days of searching, Ros eventually finds Cindy working in an Italian bar and she and Ian concoct a plan to abscond with Ian's children. They lure Cindy into a trap, while Phil Mitchell and Grant Mitchell kidnap Steven and Peter and bring them to the airport to reunite with their father. Despite a few hitches, Ian manages to bring the children safely back to Walford, with Cindy in pursuit.

Cindy threatens to take Ian to court for custody of the children. Ian continues to use Ros to investigate Cindy and her new partner, Nick Holland —a rich businessman who is funding the custody case. Ros also begins investigating Ian's hitman, John Valecue (Steve Weston), who is now being held in prison for an unrelated murder. Valecue is unwilling to admit that Cindy hired him to kill Ian, as his sentence will likely increase if he admits to his involvement. However, after Annie Palmer threatens him with severe repercussions from her associates within the prison, Valecue eventually confesses. Cindy is arrested and imprisoned, and Ian is given custody of his children. Ros is not seen again following the completion of the case.