In 1883, a little-known Indonesian volcanic island called Krakatoa exploded with enough force to be heard nearly 3000 miles away. Doug and Tony materialize days before this explosion, and meet a professor there to investigate the volcano with his lovely daughter - and a small group of superstitious natives. After a recent major eruption, Professor Holland is sure the volcano's next explosion is decades in the future, and cannot be persuaded otherwise - but he may be deceiving everyone, even himself. Then Doug and Tony discover an error in the date calculations that suggests they're far closer to the fateful day than they first thought.

Doug and Tony hurtle nearly 3000 years futureward to the Montana of 1876, days before the Battle of the Little Bighorn that will cost General George Armstrong Custer and his men their lives. Doug tries to persuade Custer away from his ruinous course while Tony attempts to convince the Lakota he landed among that he is an honorable man and that there is nothing to be gained from battling Custer.