On the 12th the 61st Brigade was relieved by the 60th and went back to Carnoy. Here on the afternoon of the 15th the whole camp of the 12th King’s was wrecked by an explosion between the officers’ huts and the men’s camp. It is unknown what caused the disaster, but apparently some explosives which had long been buried were detonated by accident. Fortunately many of the officers and men were away at the time, either at a football match or at the Carnoy Coliseum, where the “Verey Lights” had been performing since the 20th of February. This must have saved many lives. Nevertheless, three officers were killed and one wounded, and nine men killed, 52 wounded, and one reported missing. Since the beginning of March there had been increasing signs that the enemy was preparing to withdraw along the whole of his front in the Somme area. Arrangements were therefore made for an early advance. Orders were issued for the formation of advanced guards; the lines on which the operations should be carried out were laid down, and patrols were kept constantly at work to give immediate information of any retirement from the German positions along the Divisional front. CHAPTER VII THE GERMAN RETREAT _17th March to 1st July 1917_ The German retreat to the Hindenburg Line--Arrival of the Divisional Machine Gun Company--Actions at Neuville and Ruyaulcourt, at Metz-en-Couture, at Trescault and at Bilhem--The Division in the line facing Quéant under IVth Corps of Fifth Army. (_Vide_ Maps II and III.) At dawn on the 17th of March the German retreat on the 20th Divisional front began. The enemy withdrew from his positions very rapidly and with great secrecy. On the 14th the Guards on the right had occupied the western edge of St Pierre Vaast Wood and the south-east end of Saillisel; on the 15th they had advanced to the east side of the wood; patrols of the 20th Division, however, found the enemy still holding his front line up to 5 A.M. on the 17th. The Australians on the left then reported that they had advanced; immediately patrols were sent out again, in broad daylight, up to the German line. This time they found it unoccupied. The enemy was at once followed up. Along the whole British line from Monchy au Bois, ten miles south-west of Arras, to the right an important advance was made. The French took Roye, meeting with little opposition. British troops on the right of our line entered Chaulnes; XIVth Corps occupied the Le Transloy trench system, and troops of the Fifth Army were in Bapaume. The 20th Division established a line of outposts 600 yards east of the Peronne-Bapaume road and parallel to it, including the town of Le Transloy; on the right the Guards were east of St Pierre Vaast Wood; on the left the Australians were in Beaulencourt and Villers au Flos.