A train trip over Donner Pass was not something undertaken lightly in 1876, but there were far greater threats than blizzards and avalanches. Nate Poole found himself caught up in a struggle between a beautiful, mysterious woman from the distant future and the inhuman policeman who came back in time to arrest her. What was worse was the part he had to play in their struggle: it was unlikely any of them would live to reach San Francisco.