A hush, a chill falls upon the staff. A cavalry squad is sent to reconnoiter; but before it has even cleared itself of the French lines, a prisoner taken by Marbot’s hussars is brought to the Emperor. This prisoner was the bearer of a letter from Bülow to Wellington to announce the arrival of the Prussians! Even now the Emperor does not realize his danger, does not suspect the truth of the situation, for he believes that Grouchy is so maneuvering as to protect the French right and to prevent the Prussians from falling on his flank. Napoleon sends him the dispatch: “A letter which has just been intercepted tells us that General Bülow is to attack our right flank. We believe we can perceive the corps on the heights of Chapelle-Saint-Lambert. Therefore do not lose a minute to draw nearer to us and to join us and crush Bülow, whom you will catch in the very act.” Immediately the Emperor detached the cavalry divisions of Domon and Subervie to the right to be ready to hold the Prussians in check, and the 6th Corps (Lobau) was ordered to move up behind this cavalry. _Thus from half-past one in the afternoon Napoleon had two armies with which to deal._ Had he suspected that Blücher had left Thielman’s corps to amuse Grouchy while the bulk of the Prussian army was hastening to join Bülow on the right flank of the French, the Emperor would probably not have gone deeper into this fight. Expecting every moment to hear the roar of Grouchy’s guns in Bülow’s rear, the Emperor now ordered Ney to the grand attack on the English line. Eighty cannon thundered against Mont-Saint-Jean, and the English batteries roared in reply. For half an hour the earth quivered with the shock, and in Brussels, twenty miles away, every living soul hung upon the roar of the guns. Merchants closed their stores; business of all sorts suspended; eager crowds hurried to the Namur gate to listen, to question stragglers from the front; timid travellers, who had come in the train of Wellington’s army, hastily secured conveyances and fled by the Ghent road. In the churches, women prayed. Is Blücher the only man who could play the game of leaving a part of his troops to detain the enemy? Cannot Grouchy leave 10,000 men to die, if necessary, in holding Thielman, while with the remainder he pushes for the distant battlefield? There are those who say he could not have arrived in time had he made the effort. How can anybody know that? Certainly his cavalry could have covered the distance, and the infantry in all probability would have arrived in time to take the exhausted English in the rear, after their advance to La Belle Alliance, and cut the surprised troops to pieces.