Life and death, love and relationships. It’s what good chick flicks – and Grey’s Anatomy – are made of. Life affirming moments and boxes of tissues are never far away for fans of this impressively long- running medical drama. Faltering Hollywood star Katherine Heigl must surely be kicking herself that she abruptly quit the series all those years ago. Tonight, Callie ( Sara Ramirez) decides to stay on the brain mapping project and asks Derek ( Patrick Dempsey, left) to help. Meanwhile, Meredith ( Ellen Pompeo) is at a crossroad – with her own project and her relationship with Cristina ( Sandra Oh). It’s a friendship that might be battered beyond repair.