Meanwhile the II. German army had received its orders to march in a line of army corps on a broad front in the general direction of Pont-a-Mousson, well to the south of Metz. The I. army was to follow by short marches in echelon on the right; only the III. corps was directed on Falkenberg, a day's march farther towards Metz along the St Avold-Metz road. The movement was begun on the 10th, and towards evening the French army was located on the right front of the III. corps. This entirely upset Moltke's hypothesis, and called for a complete modification of his plans, as the III. corps alone could not be expected to resist the impact of Bazaine's five corps. The III. corps therefore received orders to stand fast for the moment, and the remainder of the II. army was instructed to wheel to the right and concentrate for a great battle to the east of Metz on the 16th or 17th. Before, however, these orders had been received the sudden retreat of the French completely changed the situation. The Germans therefore continued their movement towards the Moselle. On the 13th the French took up a fresh position 5 m. to the east of Metz, where they were located by the cavalry and the advanced guards of the I. army. Battle of Colombey-Borny. Again Moltke ordered the I. army to observe and hold the enemy, whilst the II. was to swing round to the north. The cavalry was to scout beyond the Moselle and intercept all communication with the heart of France (see Metz). By this time the whole German army had imbibed the idea that the French were in full retreat and endeavouring to evade a decisive struggle. When therefore during the morning of the 14th their outposts observed signs of retreat in the French position, their impatience could no longer be restrained; as at Woerth and Spicheren, an outpost commander brought up his guns, and at the sound of their fire, every unit within reach spontaneously got under arms (battle of Colombey-Borny). In a short time, with or without orders, the I., VII., VIII. and IX. corps were in full march to the battle-field. But the French too turned back to fight, and an obstinate engagement ensued, at the close of which the Germans barely held the ground and the French withdrew under cover of the Metz forts.