A new railroad line is coming to Hansen's Bend--and the Old West will never be the same. Especially for the Callahans. They've been running the local wagon train outfit for years. But now a pompous rail boss named Arbuckle wants to put them out of business. This big-city weasel mocks the Callahans' "slow-poke" wagons--and bets he can finish laying track all the way to the end of the line before Callahan's wagon train even makes it over the mountains....