Blade and fist swinging, Felix battled his way toward the chapel’s high doors. Seeing their leader so far out ahead of them, the Primaris Space Marines let out a war shout and pressed on, bludgeoning their foes with rifle butt and combat blade when the range became too close to effectively fire.

Cutting the head from a power-fist-wielding plague champion, Felix made the chapel doors first. He raised his sword and shouted, ‘For Guilliman! For Ultramar! For the Emperor!’

The battle was done soon after.

Felix set a rearguard before going into the chapel with Maxim and Gerrundium. The dead were moving still. Their progress was slow, but they were coming on inexorably.

Having positioned his men, Felix returned to the feasting hall and the doorway that led into the chapel. Maxim solemnly pushed open the door, and together they were confronted by the daemonic mechanism of Mortarion.

All fittings had been stripped from the chapel, leaving it a bare chamber with chipped walls where mosaics had been torn free and murals smashed. Plaster crunched underfoot.

Plinths empty of statues held strange alembics. They bubbled furiously, emitting cool smoke that smelled of sickness. They were arrayed at precise intervals, seven in all, surrounding a huge thing made of brass, wickedness and glass. Its lower part was an immense half globe, full of swirling black particles that, on closer inspection, proved to be evil-tempered flies. The smokes of the alembics were conveyed to this chamber by tubes of moist leather, though whether this was to feed or to kill the flies could not be discerned.

Towering proudly from the seething mass of bottled flies rose a complicated mechanism of verdigrised bronze and brass. Seven cracked white dials were mounted on the upper parts, their faces divided into seven portions.

As technology, the machine’s exterior appeared elegant but primitive, something from a backward world of steam and clockwork. In the centre was a network of fluid circuitry of more sophisticated alien manufacture, though what that held inside was the most esoteric and primitive of all. The xenos circuitry encased a glowing shard of what looked like stone. It had no deliberate shape, appearing natural, or at least created using poorly refined growing processes, but the curve of it – the bladed end and the knotted parts spaced down its length – suggested a monster’s finger hacked from a cruel talon. Spiral wires were plugged in to crudely drilled holes in several places. Crowning it all was complicated network of gears that drove three brass orbs around and around, like an orrery depicting a system of a few planets.

The combination of sciences was bizarre. Such was the mix of technologies employed in the machine’s creation, from the most advanced secrets to the lowest tech base, that were it not for the aching green glow coming from it, and the sense of palpable evil that accompanied this fell light, it could have been taken for some dramatist’s stage prop.