Both born in New York City in 1859, William Tweed Bonnifield acquires the nickname Willie the Kid when he emerges from the womb laughing, but William Henry McCarty won't be christened Billy the Kid until he becomes notorious many years later. The fatherless boys meet in an Indianapolis classroom when Billy hits Willie with a hard-boiled egg and Willie doesn't snitch. They become bosom buddies, and their mothers, Charlotte and Catherine, bond as two struggling "widows." Mischief maker Billy proves popular with boys and girls alike. Well-behaved Willie looks for direction, for better or worse, from Billy. After Indianapolis, the close families stay connected in Wichita, Kansas, and Denver, Colorado, before venturing to New Mexico Territory. In Santa Fe Catherine marries would-be gold prospector Bill Antrim; later, in Silver City, Charlotte weds carpenter Fred Schellschmidt. Willie and Billy must deal with growing pains, worrisome mothers, indifferent stepfathers, Wild West hard cases, teachers, lawmen, and a deadly case of consumption. When his mother dies, teenaged Billy is set adrift, commits a minor crime, escapes jail, and runs off to the Arizona Territory. Of course, his best pal comes along. But how long can they stick together? The bolder of the two is destined to become the infamous Billy the Kid. But will Willie the Kid follow the same outlaw path or will the boyhood amigos live out different lives in New Mexico? Includes Readers Guide.