The Last Frontier finally revealed how Frank's 8-year-old daughter died - in a brutal shooting that viewers watched unfold. During the Friday, November 14, episode of the Apple TV+ series, a flashback showed Frank (Jason Clarke) driving up to an ice cream parlor with son Luke (Tait Blum) and daughter Ruby in Chicago. They were enjoying the dessert when Ruby needed to go back into the car to write something in her journal, which is when some men drove by and shot at the vehicle. Ruby was fatally injured and Frank pulled her body out of the car.