I was really impressed by this movie. As stated earlier by others the movie was interesting till the end. The only glitch not mentioned at this site is the plot starting the story; appointing the killer as a Wehrmacht General, due to recognition of the red piping on the officers breeches. The German army had the strange habit of issuing/allowing red piping to all officers working at/(permanently)assingned to generals's staff's, making the group of suspects quite larger. In this story the makers could have better used the sighting of a glimp of a general's collar patch (these are typical for general's ranks, though the one of GeneralFeldmarschall differs, Rommel carried the wrong ones in this movie as well). Another remarkable fact is the name of the SS-unit; "Nibelungen". This unit actually existed, as the 38 SS-grenadiers division. The division was formed on 27 March 1945 from personnel and students of the SS-Junkerschule Bad Tölz (SS-military academy). The name 'Nibelungen' came from German mythology, which was the name of a lineage of dwarfs, who were defeated by Siegfried (which was in line with the "Wagnerian" and "Germanic" line of thinking by both Hitler and Himmler). Although the transformation of a "General-lieutnant der Wehrmacht" to "Obergruppenführer" is rather unusual and strange, the unit commanded by the character played brilliantly by O'Toole was already Waffen-SS in 1942 in the movie (but commanded by a Wehrmacht general at that time).
With this said i still much recommend this movie to all in favor of classic war-movies. Two thumbs up!