Recurring characters who returned include : Jack and Claire 's father , Dr. Christian Shephard ( John Terry ) , wealthy industrialist and former Other Charles Widmore ( Alan Dale ) , Desmond 's wife Penny Widmore ( Sonya Walger ) , former Other Eloise Hawking ( Fionnula Flanagan ) , Locke 's ex-girlfriend , Helen Norwood ( Katey Sagal ) , Hurley 's former boss , Randy Nations ( Billy Ray Gallion ) , mysterious Flight 316 passenger Bram ( Brad William Henke ) , Sayid 's wife , Nadia ( Andrea Gabriel ) , deceased Frenchwoman Danielle Rousseau ( Mira Furlan ) , science teacher Leslie Arzt ( Daniel Roebuck ) , the Others ' doctor Ethan Rom ( William Mapother ) , Ben Linus ' father Roger ( Jon Gries ) , mercenaries Martin Keamy ( Kevin Durand ) and Omar ( Anthony Azizi ) , and Vincent , a dog who survived the crash of Flight 815 and lives on the island . Numerous recurring characters who reprised their roles for the final season include : Jack and Claire 's father , Dr. Christian Shephard ( John Terry ) , wealthy industrialist and former Other Charles Widmore ( Alan Dale ) , Desmond 's wife Penny Widmore ( Sonya Walger ) , former Other Eloise Hawking ( Fionnula Flanagan ) , Locke 's ex-girlfriend , Helen Norwood ( Katey Sagal ) , Hurley 's former boss , Randy Nations ( Billy Ray Gallion ) , mysterious Flight 316 passenger Bram ( Brad William Henke ) , Sayid 's wife , Nadia ( Andrea Gabriel ) , deceased Frenchwoman Danielle Rousseau ( Mira Furlan ) , science teacher Leslie Arzt ( Daniel Roebuck ) , deceased one-eyed Other Mikhail Bakunin ( Andrew Divoff ) , the Others ' doctor Ethan Rom ( William Mapother ) , Ben Linus ' father Roger ( Jon Gries ) , mercenaries Martin Keamy ( Kevin Durand ) and Omar ( Anthony Azizi ) , and Vincent , a dog who survived the crash of Flight 815 and lives on the island .