Siege of Vraks - The Mine of Sector 57-44: Failure in sector 55-46 did not stop the progress of the underground war in other sectors, and every regiment now had engineer companies attached and at work below ground. There was a second frontline forming below the trenches, and the stealthy tunnel fighting continued day after day, extracting its toll of attrition from both sides, but with the Krieg engineers slowly progressing towards their ultimate objective - the curtain wall.The curtain wall itself was no single defence line. Over the long years of the war the curtain wall, a tall, thick defence bristling with weaponry and housing bunkers and barracks, had been reinforced with extra trenches and pillboxes laid in front to form another formidable defence line. If not as thick as the previous three, still it must be taken by direct assault.Marshall Kagori’s plan had always been to undermine the curtain wall, lay large mines and blast breaches through it. Hammering it with siege artillery and bombing it from the sky might work, but would redirect resources that were always in demand elsewhere. Until such time as the trenches could be dug closer to the wall and it could be targeted by direct fire, then a large mine posed the best chance of making a successful breach.On 673826.M41, over one patient year after the mining operation had first begun, the objective was reached. In sector 57-44 the 383rd engineer company reported it had located the wall’s deep foundations and was in position to set a mine and attempt a breach. Working in total secrecy and silence the engineers ferried the explosives to the chamber constructed to house them. Each explosive charge was carefully stacked and a secondary detonator attached back to the main detonator. It took many days of stealthy work to build the mine. Meanwhile, on the surface an attack was being prepared by the 308th Siege Regiment. It would fall to them to lead the way and force a route through the last defences between the fortress and ultimate victory.Preparations for the attack were a closely guarded secret, only the engineers of 383rd company were aware of what was actually being planned. Across Vraks other mining operations were stepped up, to draw enemy attention away whilst the mine was readied. In sector 56-46 heavy cutters were used in a sudden drive for the curtain wall as a deliberate diversion. Quickly spotted by the enemy it drew several counter-mines to it and provoked more bloody underground firefights.The 57-44 mine would be the largest yet, a massive amount of explosives were needed to make a wide breach, almost emptying 34th Line Korps' stockpiles. They would have one shot at it and they had to make it count!714826.M41 was set as zero-hour for detonation. The 34th line korps’ high command gathered in a distant bunker to observe the mine and subsequent attack from a safe distance. The cables were checked and double-checked and all engineers removed to safety as the countdown grew ever closer to zero. Over the Vox-casters a warning was broadcast - until "10, 9, 8, 7, 6... 2, 1 - Fire!"A tornado howled down the underground tunnels, blowing earth and rock back through the entrances. The ground began to tremble violently as a yellow flame shot hundreds of feet into the air, followed quickly by dense columns of smoke and then the debris behind it. Growing like a mountain in the sky, the black column of rock, earth and masonry rose, up and up, ever upwards, forming a broad mushroom cloud until it peaked and began to tumble back down. With a great booming crash the shock wave rolled out across no-man’s land, rattling the dugouts and trenches of 308th regiment as it swept over them. In the distance all was obscured by the dense pall of smoke and gas now expanding from ground zero. As the smoke cleared the observers could see that the curtain wall had gone. A huge stretch of it had been obliterated into shards of masonry. Nothing remained except a yawning crater. It was a scene of complete devastation. The mine had done its work, 88th army had their breach, now they had to seize it.The guns of 308th Regiment opened fire as one. The barrage that signalled the start of the attack impacted beyond the curtain wall, shells bursting in rapid succession as the artillery prepared the ground for the first wave of infantry in their Gorgon transports.