The Emperor was in a pensive, somber mood, riding upstream from Kovno to select a crossing place over the Niemen River. Removing his familiar colonel's coat he put on the jacket and black silk kalpak of a Polish lancer. His companions—who all advised against this invasion, Berthier, Davout, Caulaincourt, and the engineer Haxo—did the same. Galloping back to headquarters, a startled hare got under his horse, causing him to fall. This was an inauspicious portent that would have stopped a Roman general in his tracks.