For Aidan O'Brien it had been a week of mostly ups, with one major down. On Friday morning, the winter favourite for the Derby, Luxembourg (Ire) (Camelot {GB}), was found to be lame behind after exercise, having been shortened in the betting for Epsom following his third-placed finish in the 2000 Guineas. By Sunday he had been ruled out of the Derby completely, just as another potential star emerged from the Ballydoyle battalions in the hugely impressive Stone Age (Ire) (Galileo {Ire}). A maiden until the end of March on...