The accident of the battle arose from the fact that the British Fleet was simultaneously on 31 May engaged in one of its periodical sweeps through the North Sea. It had already turned back towards its northern bases when at 2.20 p.m. enemy vessels were signalled to the east. Beatty, who had under his orders the four "Cats," Queen Mary, Princess Royal, Lion, and Tiger, together with two other battle-cruisers, the Indefatigable and New Zealand, and the four biggest and newest battleships, Barham, Warspite, Valiant, and Malaya (the Queen Elizabeth herself was undergoing repairs at Rosyth), at once turned back south-eastwards to cut off the enemy from his retreat along the Jutland coast. The enemy vessels were Hipper's cruisers, and they also turned south to fall back on their battle-fleet, at whose proximity Beatty can only have guessed. At 3.48 the action began with Hipper's battle-cruisers, Derfflinger, Lutzow, Moltke, Seydlitz, and Van der Thann; none of them carried heavier than 12-in. guns, while Beatty's "Cats" had 13.5-inch and his Queen Elizabeths 15-inch guns. A light-cruiser attack against our line was crumpled up by corresponding vessels, but the bigger German ships escaped fatal damage from our heavier fire (it took hours to dispose of the enemy at the Falklands), and by 4.42 they were in sight of their battle-fleet. Beatty's business was now to turn and draw the Germans northwards into Jellicoe's jaws, but the turning in face of the German battle-fleet was a critical manoeuvre. Beatty's battleships were north-west on his starboard quarter, and as his battle-cruisers turned they masked the Queen Elizabeths' fire while exposing themselves to the concentrated attention of the German Fleet. A high-angle shell fell on the thinly protected deck of the Queen Mary; she blew up and sank in a few seconds. Another fell down the ammunition shaft of the Indefatigable with the same appalling result. Beatty was not deflected from his course; possibly no other could have been taken. The rest of his cruisers got round without mishap, and the brunt of the fighting now passed to Evan-Thomas's Queen Elizabeths, who stalled off the whole German Fleet as both forces steamed north in Jellicoe's direction. It was probably during this stage that most of the damage was done to the German Fleet. The Lutzow and the Pommern were sunk; the battleship Konig was so battered that her forecastle was only 61/2 feet above water when she struggled into port; and the Seydlitz and the Derfflinger were in little better case.