The 3rd Battalion had breakfasted, water-bottles had been refilled, and the companies were beginning to get ready for the advance, when this blanket of fog came down. At zero hour, 4.53 A.M., the barrage opened up and the attack began. Captain Smith, who commanded C Company 15th Battalion Tank Corps (Mark V. Star Tanks), arrived at Battalion Headquarters, and reported that his tanks had been delayed by gas in Coseul Valley, so that they would not be able to advance with the Battalion as arranged, but that they would endeavour to overtake it on the second objective. The Battalion started off with No. 3 Company under Captain Tufnell on the right, No. 4 under Captain Hirst on the left, No. 2 under Lieutenant Adair in support, and No. 1 under Captain Fryer in reserve. The fog was as thick as ever, and the smoke shells in the barrage increased its density. Keeping direction by compass was tedious and difficult, since it necessitated the removal of the steel helmet and box respirator, and even then it was far from accurate. To add to the difficulties, there were several pockets of German machine-gunners, which had been missed by the 1st Battalion Scots Guards in their advance, and which suddenly loomed out in the mist often in rear of the Battalion as it advanced. No. 12 Platoon captured two machine-gun posts in the first objective, and the markers under Lieutenant de Geijer, the Intelligence Officer, found German machine-gunners still holding out to the west of the second objective, in the area where the Battalion should have formed up. The 1st Battalion Scots Guards had captured the right and left of the second objective, but owing to the fog the centre was still in the hands of the Germans. The 1st Battalion Scots Guards, on finding out what had happened, soon cleared out these Germans with the aid of No. 1 Company (the Reserve Company). By 6 A.M. the Battalion Headquarters had reached its destination, namely, the two trees between the first and second objectives, but was unable to get in touch with any of the companies. Tanks were moving about in the fog, and the Lewis guns were engaging the German machine-guns at close quarters, and were firing indiscriminately into the fog. To give an example of how confusing the situation was, the Battalion Headquarters was charged from the front by two platoons of the Scots Guards, who mistook it in the fog for a German machine-gun post. By 7.30 No. 2 Company, under Lieutenant Adair, had gone through the junction of the 1st Battalion Scots Guards and 1st Battalion Coldstream, and was advancing on its objective, which was the valley between the railway and Moyenneville. A little later Captain Tufnell and Captain Hirst reported that Nos. 9 and 12 Platoons of No. 3 Company and all No. 4 Company were near Moyblain Trench, having completely lost their way. No. 11 Platoon had also lost its bearings, and after moving round in a semicircle, was discovered heading towards the rear instead of towards the front.