Fortunately the plot was betrayed by a Brahman to the British authorities, and the scheme was defeated. On the morning of the 15th of May, the sepoy regiments in the cantonment at Mian Mir were drawn up on parade as usual. Suddenly, they were ordered with a loud voice to lay down their arms. Before them was a thin line of European infantry which presently fell back, and revealed the mouths of twelve guns pointed at the sepoys with lighted fires. The European infantry began to load their rifles behind the artillery, and the sepoys could hear the clicking of locks and ramrods. The would-be rebels saw that the game was up. They threw away their muskets and sabres in sheer terror. More than 3,000 Asiatic sepoys, who were preparing to murder their officers, had surrendered their arms to less than 600 Europeans. The plot in the fortress at Lahore was crushed in a like fashion. The European guards had been strongly reinforced by a detachment from the regiment at the cantonment at Mian Mir; and the two sepoy battalions were disarmed before they could unite for the slaughter of Europeans. [Sidenote: Chamberlain's flying column.] Later on it was found that all the Bengal sepoys in the Punjab were more or less tainted. Measures were taken to avert or counteract the evil. Suspected regiments were removed to localities where the Sikhs were most hostile to the Bengal army. A flying column of Europeans, Sikhs and others, was organised to act against threatened points and overawe intending mutineers by rapid movement and vigorous action. In the first instance it was commanded by Brigadier Neville Chamberlain, who rose to be one of the most distinguished officers of the time. Later on, the column was commanded by Brigadier John Nicholson, the hero of the day, who, as will be seen hereafter, was cut off in the very zenith of his fame. [Sidenote: Peshawar valley.] §15. The valley of Peshawar was another cause of anxiety. It lies in the north-west corner of the Punjab beyond the river Indus, and faces the Khyber Pass. It is the key to India, the route by which Alexander the Great and the early Mohammedan conquerors invaded the Punjab. [Sidenote: Frontier tribes.]