Task: Story Composition
Input (English): Premise: The allies invaded Fortress Europe on D-Day. 
 Initial Context: Since then their progress across France has been swift. 
 Original Ending: They've advanced almost all the way to Germany. One obstacle stands in their way, the Rhine River. A swift victory is assured once past that. 
 New ending: They've advanced almost all the way to Paris. One obstacle stands in their way, the Germany army. A swift victory is assured once past that. 
Output (English): Since their progress across France has slowed down.