Normandy Invasion

D-Day was the codename for the invasion of Nazi occupied Europe on June 6th 1944 by the United States of America, the United Kingdom, Canada and other nations.

A Changeling travelled back in time to just before the invasion and attempted to change history by warning Adolf Hitler of the invasion. He was stopped by Jake Sisko and Nog. They were assisted by an ancestor of Jean-Luc Picard.