Most men would have succumbed to the disaster, but it only spurred De Wet. He had signally failed in his late attempt on the Transvaal, and he had just lost almost everything at Bothaville, but he resolved to make a raid in the opposite direction on the northern districts of Cape Colony. To reach his new objective, he must traverse the whole length of the Free State, which, having been in the occupation of the British Army for several months, should have offered the line of greatest resistance to his movement.
The Brandwater Basin disaster of July 30 had, however, by no means crushed Free State Boerdom, which, after having been heavily hurled to the ground, where it lay for a time apparently unconscious, began to show signs of returning animation, and in a few weeks was again on its legs; thanks to the restoratives freely administered by De Wet on his return from his first incursion into the Transvaal. Into each district he sent irreconcilable men after his own heart to stimulate the wavering and animate the discouraged; and barely a month elapsed before the burghers were besieging Ladybrand, which, however, they failed to take, and were hacking at the railway into the Transvaal. In October every village in the S.W. district of the Orange River Colony in the possession of a British garrison was attacked, all but one of them without success.
Lord Roberts had already taken measures to curb the new activities. His plan was to occupy certain places strongly as bases from which mobile columns could constantly move to and fro, eating up the intervening country and rendering it incapable of supporting the enemy. Its operation was mainly confined to the northern districts of the Free State, in which lay the centre of disturbance, and the troops engaged could not be readily employed outside them. It was so far successful, in that it drove De Wet into the Transvaal in October, but it failed to restrain his subsequent movements. It probably was the best that could have been devised for dealing with local guerilla, but its action being centrifugal and not circumferential, it was powerless to deal with a meteoric raid of well-mounted men. Although the British troops greatly outnumbered the Boers, yet in practice only the mounted details, which included no regular cavalry and were relatively weak, were directly effective against the enemy, and the movements of the divagating columns were sluggish.
When De Wet left Bothaville on November 6, his arm was, metaphorically speaking, in a sling, and he was footsore; but ten days later he had brought together in the Doornberg a force of 1,500 men, with whom he proposed to cut his way into the Cape Colony. His movement south may be compared to that of a small swift steamer endeavouring to escape from a blockaded seaport. Ahead of him and on each beam were the slow-moving vessels of the blockading squadron, most of them hull down and with banked fires.
He made at once for the scene of his April successes, the country lying between Bloemfontein and the Basuto border. The chief obstacles in his way were a line of posts running eastwards from Bloemfontein, and the town of Dewetsdorp, which was held by 500 British troops. The latter he might have avoided had he chosen to do so, but he seems to have been attracted to it because it was the home of his childhood, which it was incumbent upon him to redeem from bondage.
The phenomenon of a Boer column marching through the heart of a country supposed to be effectively in the possession of the British Army was again witnessed. To borrow another metaphor, this time from Astronomy, De Wet throughout the greater part of his career was a telescopic star, invisible to the naked eye. General Officers and column commanders helplessly watched his course through the telescopes of the Intelligence Staff, and seemed to have as little power of influencing it as an observer at Greenwich has of changing the orbit of a planet. The astronomer can at least forecast with certainty the path which it will follow in the heavens, but there were no observations available from which the course of De Wet could be predicted for more than a few hours. He seemed to defy the laws of gravitation.
On November 16, he easily rushed the Bloemfontein-Thabanchu line of posts at Springhaan's Nek, and three days later invested Dewetsdorp. Meanwhile the alarm had been given. Knox's force, which had been sent after him into the Transvaal, was now sent after him to Bloemfontein, and mobile columns were detailed. Dewetsdorp was doomed from the first unless assistance arrived from outside. The position could not be held effectively by a small force, One by one the scattered posts fell into the hands of De Wet, but the defence was maintained until the 23rd, when the white flag was hoisted. On the previous day two relieving columns had started from Edenburg, but they were checked near Dewetsdorp on the 24th by De Wet, who shook himself free of them and was soon on his way to the south with 500 prisoners of war; and Knox with a third relieving column was marching from Edenburg.
Thus almost within sight of Sannah's Post and Mostert's Hoek and after six months of apparently successful activity by the British Army, De Wet snatched away another garrison. After a repulse at Fredrikstad, soon followed by a severe mauling at Bothaville, from which he broke out as a fugitive, he placidly and confidently trekked southwards unopposed for 150 miles, magnetically attracting to himself a force sufficient to blot out Dewetsdorp in the presence of a bewildered enemy, who, though in overwhelming numbers, was feebly strung out in lengths without breadth. The British Army had still to learn, not only in the Free State, but also elsewhere, the elemental fact in geometry that neither one straight line nor two, nor under certain conditions even three, can enclose an area.
It was evident that De Wet was making for the Cape Colony, the disaffected northern districts of which were again giving cause for anxiety, and which at all hazards he must be prevented from entering. Lord Kitchener came down from the Transvaal to direct the operations; the Brigade of Guards on its way to Capetown and home, was de-trained to hold the line of the Orange; Knox's columns hurried forward. De Wet, after a slight encounter with Knox, who was marching south, turned adroitly to the west and did not resume the original direction of his march until he had put a considerable distance between himself and the columns, which were "running heel" and pursuing him almost in the opposite direction. Near Bethulie he was reinforced by Hertzog and other leaders, but by this time he had been headed by Knox at Bethulie and was compelled to draw off eastwards into the angle between the Orange and the Caledon. He left Hertzog with instructions to make his way across the river west of Norval's Pont, intending to cross with his own force higher up. He was, however, prevented by the forces of nature from carrying out the raid which the British military forces would probably have been unable to prohibit. Heavy rains had fallen in the Basuto Mountains, and the sudden rise of the Caledon and the Orange to flood level obliterated most of the drifts and entrapped him between them. He made one dash for the Orange at Odendaal, but found the drift in the possession of the enemy.
De Wet now saw that he was not destined to enter the Cape Colony on this occasion, and that he would have much difficulty in saving himself. On December 6 he determined to retreat by the way he came. He did not, however, wholly abandon the scheme of a Cape Colony raid, for he detached Kritzinger and Scheepers with instructions to hover and watch their opportunity of breaking into it. The opportune falling of the Caledon opened to him a postern towards the north, and on December 7 he crossed the river and made for Helvetia, where again he was entangled. The line of least resistance seemed to run westwards towards the railway, and he put himself upon it, soon to find that Kitchener's dispositions had obstructed it. He doubled back, and trailing Knox after him in a night march, shook himself free. Knox, confident that the Bloemfontein-Ladybrand line of posts would be an effectual barrier to De Wet's retreat, had waited to pull his straggling columns together. De Wet, reinforced by a commando under Michael Prinsloo, who had been with him in his first Transvaal incursion when Steyn was put over the border, rushed at the blockhouse line and again cut it at Springhaan's Nek, for although it had been attended to recently, there was an aneurism in it which yielded at the critical moment, and on December 14 De Wet passed freely through the lesion. He arrived by way of Ficksburg at Tafelberg, S.E. of Senekal, on December 25.