she tells how she sat so long with the boy in her arms that the sky rained down its tears and baptized him and washed him clean for the grave , and how she dug the grave with her hands in the mud at the base of the iron giant and laid him in it , and how she prepared him for heaven by cutting off his head with the gurkha knife so that he would n't get lost and wander back to the surface of the earth like so many had done-and how the brutal task caused her no suffering because she knew by then there was evil in her and that no action however grotesque or unholy could be ill-suited for the thing she had become .