The destruction of the machine gun defending the Masallamuja gate allows the Mahdi's forces to overwhelm the defenders in the redoubt and to advance along the inside of the ramparts in both directions. Those on the ramparts have to turn or descend in order to avoid being taken from behind.
With the Mahdists inside the walls, the defenders all along the ramparts are forced to re-position as well. As a result, the Kalakla gate and the muddy White Nile end of the defenses quickly give way to the Mahdi's renewed attacks there. This leaves small groups of Gordon's defenders isolated and attacked by overwhelming numbers. The forces holding the Burri gate redoubt fall back as well, in order to avoid being surrounded.
With the Mahdi's forces within Gordon's defenses, our rules permitted Gordon to relocate his reserve force that had been guarding against a river assault across the Blue Nile. He positions them to block access to the main road through the city, placing most of his strength in front of the Governor's Palace. And seeing that Fort Burri is already compromised by his men's retreat from the Burri gate, he moves his small steamer downstream to Fort Mukran, where it will be safer from capture and it can use its one small gun to support the lower city and the west end defenses. Two accounts of the siege maintain that Gordon had reserved one small steamer for a last-second evacuation of the Europeans who remained in Khartoum. So we decided to give Gordon's forces the steamer.
Outside of the city, Gordon's Krupp batteries are taken by the Mahdists, and the small remaining groups of Egyptians, armed slaves, and Bashi-Bazouks who had held the outer defenses are destroyed by the hordes of Ansar.
The Burri gate is forced and Fort Burri is quickly surrounded.
Only at the west end of the outer defenses are Gordon's forces able to conduct an orderly retreat, falling back on the lower town and Fort Mukran.
Fort Burri falls when the attackers are able to batter down the fort's gate with point-blank artillery fire.
After capturing Fort Burri, the Mahdists move on into the city, heading towards a collision with Gordon and his small reserve force, who are determined to hold Khartoum's main road.
Gordon's fire is particularly effective in the narrow streets. But the sheer number of attackers forces Gordon to retreat through the souk. He establishes a final line between the main mosque and the Coptic church, while his forces from the White Nile end of the line pull back around Fort Mukran, using the flood dike and the buildings of the lower city as defenses.
Fortunately for the two of us who were gaming Gordon's forces, the agreed-upon turn limit put an end to the violence at precisely this point in the battle. The game's end was represented by the arrival of one of the two gunboats of Wilson's relief expedition, which carried some of the Sussex regiment's troops, clad in their specially issued red coats.
The gunboat in the pictures, of course, in no way resembles Wilson's Bordein, but none of us had the energy to craft a proper model. The end of the game was a bit anti-climactic, I thought, and all four players agreed that Gordon's victory in the game was only a "technical" one. Even Wilson's two gunboats would not have been sufficient to drive the Mahdi's forces out of Khartoum at that point. That Gordon was able to hold on (just long enough) to Fort Mukran and to the seedy lower town surrounding it was credited primarily to Gordon's effective positioning(s) of his reserves and the timely retreat and reorganizing of the defenders along the White Nile end of Gordon's defenses. In the actual historical battle, it was through the muddy White Nile section that the Mahdi's forces were able to break into Khartoum. In our game, Gordon's mistake was corrected by putting a stronger force (and a machine gun) in that important spot.