To save the Pony Express, Sheriff Pat Stevens and his sidekick Sam Sloan must ride faster than ever before In a barren stretch of southern Colorado, a small shack links Powder Valley to the rest of the world. Every other day, Sam Sloan comes thundering over the range with a mail sack over his shoulder--just one link in the long line of riders known as the Pony Express. In all the time he's been riding the route, he's never been one minute late, and his perfect record has won the attention of company brass.   The Express is planning a new route linking Colorado and Wyoming, and they want Sam to break it in. The trail between Denver and Laramie is raw, with danger lurking on all sides. To deliver, Sam will need speed, ammunition, and the help of his two best friends, the one-eyed giant, Ezra, and Powder Valley's sheriff, Pat Stevens.