What happens when Washington politician Kip Chalmers insists that the stalled Comet go on through a dangerous tunnel because he has a speaking appointment in San Francisco.

Only a diesel engine could go through the tunnel safely. All that is available until the next morning is a wood burning engine. The chief dispatcher warns of the danger posed by such an engine in that particular tunnel. Chalmers wins and they find a drunken engineer who believes he can get the train through by going very fast. He was wrong and the tunnel explodes killing Chalmers and all who were in it.