Across the southern sector of the forge complex, down to the southern gateway and across the fortified grey zone, each of the skitarii embedded with the defence forces received a coded burst transmission. Sleeping soldiers awoke and quietly gathered up their weapons, while those on sentry duty drew knives or silenced weapons and turned them on their watchmates. Within minutes, gunfire crackled in the darkness as the Tech-Guard ambushed their erstwhile comrades.
At the warehouse barracks of the Astartes ground force, most of the Dark Angels were still wide awake, tending their weapons and engaging in close-combat drills in preparation for the battles ahead. The Praetorians in their midst stiffened as the signal touched off implanted combat protocols and flooded their bloodstreams with a lethal brew of combat drugs. From one heartbeat to the next, the skitarii were transformed into berserk killing machines; the virulence of the drugs were so great that within fifteen minutes it would begin to erode their muscle tissue - literally eating them alive. Until that point, however, they were immune to all but the most catastrophic injuries. Readying their weapon implants and close-combat attachments, the Praetorians hurled themselves at the unsuspecting Astartes, and the blood began to flow.
The first indication of danger in orbit was the sudden storm of vox jamming that effectively isolated each of Jonson's ships. The resupply operations had ceased for the day, but there were still several hundred tech-adepts and servitors from the forge hard at work on the Iron Duke, the strike cruiser Amadis and the Invincible Reason. Several of the warships, notably the heavy cruisers Flamberge and Duke Infemus, as well as the escort ships of the scout group, all went to battle stations, while the others initially believed that the vox failure was an accident caused by the current repairs.
As the captains of the battle group tried to sort out the sudden loss of communications and attempted to regain contact with the flagship, they were distracted from the threat that was gliding towards them out of the darkness. A small but powerful fleet, assembled in haste with whatever forces were at hand and quickly despatched to Diamat, was now stalking towards the planet with their engines idling and their surveyors silent.
The ships of the scout force detected the oncoming enemy ships first. Signalling to one another in basic code using their running lights, the light cruisers and their attendant destroyers flared their thrusters and broke orbit, their surveyors sweeping the void in case the jamming was the precursor to an enemy attack. They detected the eight ships of the enemy force just a few minutes later.
Signal lights flashed between the Imperial ships: Form line and prepare to launch torpedoes. With remarkable skill and precision the small ships raced forwards, increasing to attack speed. Below decks, servitors and torpedomen struggled to load the tubes, while on the bridge the Ordnance Officer input course and speed into the target solutions for the ship's weapons.
Within five minutes the vessels signalled that they were ready to launch. As the scout force entered optimal torpedo range the signal was given: For the Emperor - launch all torpedoes.
Orders were passed to the torpedo deck. The senior torpedomen checked their firing data and turned their launch keys.
Less than half a second later, they were dead.
As each torpedo received the electronic signal to launch, its plasma reactor overloaded, detonating its warhead inside the tube. The rakish bows of the sleek destroyers vaporised in expanding balls of plasma, transforming them into burning, broken hulks. The light cruisers fared only slightly better, their torpedo decks destroyed and fires burning out of control on their lower decks, the small squadron had no choice but to break off and try to save their ships.
The explosions signalled to the rebels that their stealthy approach was at an end. Thrusters ignited, surging to full power; void shields crackled into existence, forming shimmering spheres around their vessels like ephemeral soap bubbles before firming up and fading from view. Surveyors blazed to life, painting the surprised Imperial ships with invisible energies and feeding targeting data back to the rebel gunnery officers.
Eight ships: three cruisers, two heavy cruisers and three grand cruisers - bore down on the battered Imperial ships. Cut off from one another, uncertain if their own ammunition had been rigged to explode by the treacherous forge, the Imperials braced themselves for the rebel onslaught.
Dawn was breaking as Nemiel emerged from the Titan assembly building. He heard the distant rattle of gunfire to the south and knew that they had run out of time. All he and his squad could do now was rush to the aid of their fellow Astartes and kill as many of the enemy as they could. 'Forward!' he shouted to his squad. 'Let no one stand in our way!'
The Astartes raced down the access road towards the southern edge of the foundry sector, their weapons held ready as they searched for threats. The rumble of petrochem engines echoed amongst the buildings to the southeast, but there was no way to tell for certain where the sounds were coming from. It was most likely a mechanised patrol of skitarii, Nemiel thought, and kept part of his attention focused that way in the event they showed themselves.
High-intensity lasguns barked behind them. Brother Vardus was struck in the back by a powerful las-bolt that caused him to fall onto one knee. Marthes held his meltagun in his left hand and bent down, grabbing Vardus's upper arm and pulling him to his feet. Brother Ephrial turned and fired a long burst back the way they'd come, eliciting a scream of pain from one of their pursuers.
Up ahead, the engine sounds roared into angry life. 'Marthes!' Nemiel said, beckoning to the meltagunner.
Just then, a Testudo APC rumbled into the access road from a side lane and lurched to a halt. Its turret autocannon slewed about and spat a stream of high-velocity shells at the running Astartes. The gunner's aim was poor and he overshot the mark, sending the shells screaming over their heads, but Nemiel could see the barrel dropping as the man adjusted his aim. Skitarii in carapace armour came around the corner as well, dropping to their bellies and opening fire on the Dark Angels.
Brother Marthes ran ahead of the rest of the squad and took aim with his meltagun. A high-power las-bolt struck him in the left pauldon and left a burn across the thick ceramite. Another shot clipped him in the leg causing sparks to flare from his knee joint. The APC gunner, apparently realising the danger, adjusted his aim again and fired a burst of shells at Marthes just as he hit the meltagun's trigger. The blast cut into the vehicle's side like a power knife and detonated its fuel cells, hurling a ball of fire high into the overcast sky.
Nemiel saw Marthes stagger as two of the autocannon's explosive shells struck him in the chest. There was a double flash, coming so close together that the sound of the blasts merged into a single loud thunderclap. The Astartes staggered forward a few steps more, then fell forward onto his face. His status indicator in Nemiel's helmet display went abruptly black.
The skitarii scrambled to their feet, their armour smouldering from the heat of the vehicle's flames. Nemiel and the others raked them with bolter fire, killing several and forcing the others to retreat. As Kohl reached Marthes, he knelt and took the meltagun from the warrior's hands and tossed it to Ephrial, then laid a parting hand on the dead warrior's shoulder before rising to his feet and sprinting after the squad.
They put the burning hulk of the APC between themselves and their pursuers, then cut to the left down a side-lane to hopefully throw them off a bit further. As they came around the corner and turned south again, Askelon pointed to the sky. 'Look!' he said breathlessly.