Set in 1860 as the first wagon trains rumble into the American West, this adventure-filled novel centers on a frontier girl and the beloved pony she tries to save Born in the back of a covered wagon traveling west from Vermont, Annie Dawson dreams of someday seeing what's on the eastern side of the great Mississippi. For now, she'll have to be content living with her parents and younger brother in the Nebraska Territory at the Red Buttes Pony Express station run by her family.   That is, until her favorite pony starts going wild, and Annie's friend—Pony Express rider Billy Cody—suspects that someone is poisoning her. But who'd want to hurt gentle Magpie? Indian tribes stirring up trouble? Or the Butterfield Mail, the Pony Express rival that seems to feel threatened by the ponies' speed in delivering mail to California?   The night before Magpie is scheduled to be put down, Annie steals out to see if her half-Shoshone friend Redbird Wilson can cure Magpie's mysterious ailment. But the pony just gets worse. Unsure whom she can trust, Annie must use her wits to find the culprit before Magpie dies and other horses meet the same fate.   This ebook includes a historical afterword.