GREY'S ANATOMY - "With You I'm Born Again" -- After an unforgettable and heart-pounding season finale, "Grey's Anatomy" returns for its seventh season on THURSDAY, SEPTEMBER 23 (9:00-10:01 p.m., ET) on the ABC Television Network. In the season premiere, the hospital staff is trying to deal with physical and emotional trauma in the wake of the deadly rampage of a vengeful gunman. As Dr. Perkins (James Tupper), a trauma counselor, is brought in to help in the recovery and to assess each doctor's readiness to return to work, Derek makes a spontaneous decision to resign as Chief and rushes back into surgery, taking everything a little too fast, and Cristina buries herself in her wedding planning. (ABC/PETER "HOPPER" STONE) KEVIN MCKIDD, SANDRA OH