Book excerpt: For decades Marks & Spencer was the most successful retailer in the world. Its clothes were a byword for affordable quality and its food halls pioneered ready-prepared meals. Then suddenly they were dowdy, the staff deserted in droves and the shares plummeted - but the annual results in April 2006 show that the company is on the mend. What went wrong and how have things improved? In new chapters covering the Philip Green bid and the Stuart Rose recovery plan, and covering the Christmas 2006 trading figures, Judi Bevan reveals all.