Genevieve OReilly born January 6 1977 is an Irish actress who has worked in both the United Kingdom and Australia OReilly was cast as the understudy in director Gale Edwards production of The White Devil a week after graduating from drama school She went on to appear in Edwards Sydney Theatre Company production of The Way of the WorldOther theatre credits include The Weir by Conor McPherson at the Gate Theatre Dublin and Richard II at the Old VicRecent parts at the Royal National Theatre have been in new play Mike Bartletts 13 and as Helena wife to Andrew Scotts emperor Julian in the 2011 production of Ibsens epic Emperor and Galilean OReilly is due to perform in George Bernard Shaws The Doctors Dilemma from July 2012 OReilly has appeared in several productions filmed in Australia including both The Matrix sequels She also played the young Mon Mothma in Star Wars Episode III Revenge of the Sith and starred as Leanne Curtis in the medical drama All Saints Since moving to the UK OReilly has starred in the political miniseries The State Within played Princess Diana in the 2007 television docudrama Diana Last Days of a Princess and taken the lead role in The Time of Your Life She played CIA liaison officer Sarah Caulfield in the eighth series of BBC drama Spooks OReilly also played the character of Michelle Beadley in the remake of The Day of the Triffids that aired on BBC One in December 2009 In 2011 she appeared in the BBCShowtime comedy Episodes playing Jamie Lapidus the blind wife of a TV executive Merc Lapidus She reprised the role in the second and third series broadcast in 2012 and 2014 OReillys film credits include Right Here Right Now 2004 The Young Victoria 2009 and the 2004 science fiction filmAvatar playing the lead role of Dash MacKenzie In June 2013 OReilly appeared in the pilot episode of the international crime drama Crossing Lines cast as Detective and Interrogation Specialist Sienna Pride attached to the ICC team from Britains Scotland Yard In the final minutes of this pilot episode her character was stabbed and killed with a knife used by an American State Department employee Gerald Wilhoit Eddie Jemison who enjoyed Diplomatic Immunity while the ICC team was chasing him and searching for their abducted police colleague in the Tiergarten Park in Berlin Germany