Four Corners

Three weeks after the death of Derek Fossen, Greene faces interrogation at an M&M conference. However, Corday is the only one to suspect something wrong. Meanwhile, Carter's parents return to town for his grandfather's funeral, which Abby briefly attends. Abby has decisions to make; Luka wants her to move in with him. Weaver returns from an impromptu vacation, worried that Romano has outed her to the staff. Chen is the new chief resident. Benton deals with Cleo's meds and Jackie's problems adjusting to life after Jesse's death. The ER is filled with patients after a brawl at a talk show taping.