Warren thought that it would be necessary to diverge from the advance and take the Grobelaar slopes, and White reported that Boer reinforcements were coming in from the north. Towards evening on February 21, it seemed not unlikely that another Colenso, Spion Kop, or Vaalkrantz would soon be debited to Buller. The line of approach to Ladysmith was held by the enemy, and the British Army of relief, the greater part of which had crossed to the left bank of the Tugela, was entangled in the Colenso Kopjes, and the river loop.

Warren's general idea for the 22nd, of which Buller approved, was to attack Wynne's Hill with the 11th Brigade, leaving Horseshoe Hill to be dealt with by the artillery. Although the Boers on the Grobelaar slopes had been well pounded for some hours by the field batteries, Wynne considered that it would be unsafe to advance unless these slopes were actually taken, but he was overruled. He had also been promised support on his left rear, but only two of the battalions detailed for the purpose were at hand and these were fully occupied in offering a front to the Boers on Grobelaar, while the movement was in progress; and he advanced against the enemy's centre unsupported except by the long range fire of a brigade on Naval Hill across the river.

He had expected that the promised supports would secure his left flank by seizing Horseshoe Hill, and in default he was compelled to detach a portion of his own scanty force against it. At sunset the cutting edge of the advancing wedge was touching the enemy, but was unable to break into him, and Briton and Boer were face to face on Wynne's Hill and on Horseshoe Hill.

Reinforcements were brought up and defences were constructed during the night, while the Boers continually fired upon the confused units labouring in the darkness. The enemy had an entrenched position on Hart's Hill which enfiladed Wynne's Hill, and which Warren had not been able to take, as Buller hoped, with the 11th Brigade.

Next morning the 5th Brigade under Hart, which was in reserve near the river loop, was sent against Hart's Hill. He advanced, wherever possible, under cover of the steep left bank of the river along a trail so narrow that the men were compelled often to move in single file; and at one place, where the Langewacht Spruit enters the Tugela, it was necessary to make a detour and cross the spruit by the railway bridge, and to quit the dead ground and emerge on to a defile under heavy fire. The advance of the Brigade was retarded by the stringing out of the battalions, and from time to time Hart's Hill was shelled without seriously harming the enemy, who as usual was not posted on the apparent crest, but some distance in rear of it.

Two battalions of the 4th Brigade, which had been lent to Hart, were so far behind that as only two or three hours of daylight remained, he decided to attack without them. For impetuous gallantry the advance of the Irish regiments was not surpassed by any other exploit in the War. Working up on difficult ground to the sound of the Regimental calls, and then almost brought to a standstill by the barbed wire fences of the railway, which became a trap of death, they rushed the slope, pushing the enemy's outposts before them, and won the crest: and then in the failing light which compelled the supporting artillery to discontinue the bombardment and relieve the enemy from the pressure of shrapnel, they saw the Boer positions still above them. The crest was false.

It was a cruel disappointment to brave men who had struggled so well, but they did not flinch. A charge was made across the plateau, but it soon was withered by fire and few of the men reached the Boer trenches. Two more battalions of the 4th Brigade arrived at dawn, but the reinforcement came too late. The troops were reorganized, as far as possible, on the slope leading down from the crest, but were eventually compelled to retire across the railway to the lower ground by flanking fire, which Hart succeeded in silencing, and was able to reoccupy the dead ground below the false crest with fresh troops.

The failure of the attack did not deter Buller from pursuing his plan, and on February 24 he proposed to renew it and to operate against Railway Hill, which stands fourth in the line of hills running in a N.E. direction from Horseshoe Hill to Pieter's Hill; but by Hart's suggestion the movement was postponed, and in the end, abandoned. The greater part of his Brigade was dangerously and densely posted on the lower ground, and when during the night a surprise party of Boers opened fire, there was some fear of a general panic. The situation was precarious. The Boer line had not been pierced: on each side it outflanked Buller and fronted the Tugela loops in which the greater portion of his force was huddled. It was fortunate for him that DeWet had gone to the Modder.

On the night of February 24 began the third movement in zigzag. The general direction of the first was N.E.; of the second W.S.W.; of the third East. It was discovered that there was a path by which troops could pass east of Naval Hill down to the right bank out of the enemy's reach, and that they could cross the Tugela by pontoon. Buller then determined to transfer the bulk of his force back to the Hlangwhane side of the river over the pontoon bridge by which he had crossed to the left bank three days before. The plan involved not only the concentration of a clubbed and unwieldy force on the right bank, but also the necessity of keeping it there until the passage of the last detail allowed the pontoon bridge to be taken up and moved to the new place of crossing, three miles below.