On the afternoon of the Tuan Muda's return from Kuching, after an arduous time driving the Chinese rebels over the border, he received information that the notorious Saji was out with a head-hunting party along the coast. Prompt action was necessary, and the Tuan Muda by sunset had started in his war-boat, leaving Abang Aing and the Malays to follow. Whilst waiting inside the mouth of the Ludam, a little stream half-way between the mouths of the Batang Lupar and Saribas, for his Malay and Dayak contingents, a boat dashed past towards the Saribas. This the Tuan Muda subsequently learnt was Saji, who off Lingga had fallen in with a small boat containing a man, his wife, and their daughter. Feigning friendliness Saji approached, and when near enough attacked the little party. The man escaped by taking to the water, his wife was cut down and her head taken, and the girl was captured. When passing the Ludam Saji had noticed the Tuan Muda's boat-flag over the bank, the tide being high, and he sat with his drawn sword across the girl's throat prepared to take her life immediately if she attempted to call out, or should any notice be taken of them. On being joined by the Malays and the Balau Dayaks the coast was patrolled, and the Saribas was searched for some way up, but the head-hunters had retired.

Sadok, Rentap's stronghold, was regarded by the Dayaks as impregnable. Since the destruction of the stockaded village at Sungei Lang, he had strengthened his position there. In legend and song the Dayaks represented this place as a mountain so inaccessible, and so protected by magic, that no enemy would ever dare to assail it. Rentap had gathered about him all the disaffected Sekrang Dayaks and some of the Saribas of the interior, who offered him aid so long as he occupied this eyrie, which stood as an unapproachable nucleus and basis far removed from danger, and to which they might all retire in case of need from the rule of the white man, that thwarted their head-hunting and marauding propensities. Rentap was entitled the Inland Rajah, and was the centre of all opposition to the rule of the Rajah of Sarawak. His fortification was near 5000 feet above the sea, with precipitous approaches on almost every side.

The Tuan Muda had obtained permission to undertake another expedition against this stronghold. His intention was to pass over the mountain, lay waste the country at the head of the Saribas, and, after so cutting off Rentap's supplies and reinforcements, to attempt the chief's position on his return.

In the Saribas, which was still a hornet's nest, affairs were coming to a head. The Dayaks were about to retire into the interior with the Datu Patinggi of Saribas, who, together with the Laksamana, was encouraging the Dayaks to continue in their evil courses. But for the Malays, and even amongst them there were many inclined to a life of peace, though these were in a minority, the Dayaks of the lower Saribas would have submitted to the Government, and amongst the latter the Rajah could now count many adherents; but the power of the evilly disposed Malay chiefs, headed by the Patinggi, and of the Dayak chiefs, headed by Rentap, was dominant in the Saribas. To check them the Rajah took a large force to that river, and went at the time that the Tuan Muda was starting on his expedition, so as to disguise the object of the latter's preparations, by leading the people to suppose that his intention was to support the Rajah; and to be at hand to attack the Saribas Dayaks in rear should they muster in force to assist Rentap. The Tuan Besar at the same time went to the Rejang, to hold the Dayaks of that river in check.

The Tuan Muda took no Europeans with him, fearing that the fatigue of the difficult overland march might knock them up, and cause them to become encumbrances; his force consisted of 3500 Dayaks, and 500 Malays, all willing volunteers, though many conceived the task to be beyond their powers; but where he went they were ready to follow, confident that under his direction they would be well led.

The expedition started on June 2, 1857, a little over three months after the Chinese insurrection, and left Sekrang in drizzling rain; throughout it encountered miserable weather, which damped the ardour of the force. The Malays especially cannot endure wet, a few days' exposure brings on fever and ague, and the cold, to which the Dayaks would be exposed on the mountain, was likely to so numb them as to render them useless.

Old Sandom was once more the guide. He had his personal wrong to avenge, as we have already stated. "Iron Anchor" and Pangiran Matali were again the leaders.

On June 5, the boats were drawn up at Sungei Antu, on a little island of rubble and brushwood, upon which a stockade was erected, and where the flotilla was to be left. Forty men, well armed, were deputed to take charge of the boats and baggage in this extemporised fort, whilst the rest moved overland in the direction of the mountain. On the 7th of June, a height, the bold ridge on which the enemy had established himself, came in sight, with a succession of hills intervening like a chopping sea turned to rock. It was resolved to push on that day to Rapu, the northern termination of the mountain, and there to establish a stockade from which parties might descend and devastate the country of the hostile Saribas, on which Rentap had to depend for supplies. But it was not found possible to do in one day what was determined. The mountain was indeed reached, but ascended only by some of the advance party of Dayaks, who could not be restrained, and who scrambled up the side to the summit of the hogs-back, to be driven back with great loss, not of lives only, but of confidence and courage as well. The bulk of the force was constrained to bivouac in rain and cold on the mountain flank.

The last hundred yards were almost perpendicular, and when mounting I had to pull myself up with one hand by the stunted trees; added to this, there was a declivity of thousands of feet on each side. In ascending this part not more than twenty men were with me. My best fort-man was wounded by a spear, and to assist him many of the others had left me. And now I must give credit to the Lingga people, for they were close at hand. I was within about five yards of the enemy, who were pitching spears from behind some wood on the brow of the hill, while we were underneath, and the spears went flying over my head and struck some of our party in the rear. Here I stood propped up against a tree, and poured thirty rounds from my smooth bore as fast as I could load. After this I tried to ascend, but the Linggas literally collared me. The enemy were quieted, so here we sat on the side of this hill, at an angle of 80°, the whole night. A few cross sticks were placed for me to sit on. One man held a shield at my back.

When morning broke the Tuan Muda and his followers succeeded in reaching the summit of the mountain, and could look along the brow to the opposite end, where stood the stronghold of the redoubtable Rentap, to which the enemy had retired. Several of the attacking force had been killed or wounded on the previous day, and over a hundred had rolled down the steep sides, and in so doing lost arms and ammunition.