Towards the end of the war in Europe, Hitler launched a last great offensive through the forest of Arden. The hilly, thickly wooded terrain was considered by the Allies to be impenetrable by tanks. Against the advice of his generals, who pointed out that there wasn't enough fuel to sustain an attack as far as Antwerp, which would have severely damaged the Allies' position, Hitler threw everything he had together, including the invulnerable Tiger tanks and his remaining elite troops of the SS.
The attack caught the Four American divisions in the lightly defended area by surprise, resulting in mass retreats, multiple POWs, and isolated pockets of fierce American resistance. The German advance created a bulge in the front line, finally clipped off by Patton from the south and Montgomery to the north. The Allied advance continued.
That's the story everyone interested in the war knows about. But this episode, narrated by Robert Powell, is from the series called "Secrets of World War II." (There are no talking heads, just Powell's narration, which is accurate and concise.) I don't know exactly how "secret" some of the revelations are. It's common knowledge that Montgomery and Patton were rivals but maybe not all of us are aware of how deep that bitterness went. The film doesn't minimize it at all. Monty was a stick in the mud and Patton "a playground bully." Both had contempt for Eisenhower as a "desk general" not a fighting soldier.
There are other revelations, even more surprising. The Allies actually KNEW that an offensive was building east of the Ardens because the code breakers at Bletchley Park, both British and American, were routinely decoding both military and railway radio traffic. But, like a partially completed jigsaw puzzle, there were enough pieces missing that the overall picture could be ignored by Montgomery, Eisenhower, and Bradley -- and it was. To the upper echelon, it was inconceivable that the German army could mount a major offensive at this late stage of the war, so they could safely dismiss the intelligence.
Due credit for stopping the German advance is given to the usually neglected combat engineers. These troops weren't simply bridge builders and telephone linemen. They were soldiers who worked under fire and often acted as ordinary infantry. They were responsible for the destruction of the bridges that the Germans had planned to use for their armor, and it slowed them down until they ran out of fuel.
Neither the code breakers in England nor the responsibilities of the combat engineers was exactly secret, but they're almost always neglected in documentaries dealing with the battle.
The first fifteen minutes or so are given over to setting the stage for the Battle of the Bulge, beginning with the landings at Normandy, and sketching in the characters of the German and Allied commanders who were to be involved.
It's a relatively short film. And frankly I think they did a fine job.