"One of the world's shrewdest and most amusing detectives" has nine days to save an innocent man from death row ( The New York Times).   On a steamy day on Staten Island, a speeding car tears past a couple of beat cops and smashes into a delivery truck. In the front seat is Andy Rowan, pale and unconscious. In the back is a blonde—beautiful, naked, and dead.   She was an aspiring Miss America, minted in the wilds of Brooklyn, and he was the press agent who wanted to make her a star. Now she will never walk a runway again. Police, judge, and jury all consider the case open and shut, and a year later, Andy's awaiting his turn in the electric chair. But Hildegarde Withers, a retired schoolteacher with a zest for crime, believes the frightened little man innocent of the killing. She has nine days to save his life. It will take a miracle, but Miss Withers has worked miracles before.   The Green Ace is part of the Hildegarde Withers Mysteries series, which also includes The Penguin Pool Murder and Murder on the Blackboard.