The door was still unlocked from when David had fled. The militia had not expected this, and had tried to break down a door which did not resist them. They fell, sprawling and idiotic.

There was a confused moment. The three militia scrabbled to stand. Outside, the squad of officers gaped stupidly into the building. On the ground floor, Derkhan and Lemuel stared back at them. Isaac looked down at the intruders.

Then everyone moved.

The militia outside in the street recovered their wits and rushed the door. Lemuel flipped David’s huge desk onto its side and hunkered down behind the makeshift shield, priming his two long pistols. Derkhan ran towards him, diving for cover. Yagharek hissed and stepped backwards from the rail of the walkway, out of sight of the militia.

In one slick movement, Isaac turned to his laboratory worktable and scooped up two huge glass flasks of discoloured liquid, still spinning on his heels, and hurled them over the rail at the invading officers like bombs.

The first three militia through the door had regained their feet, only to be caught in the shower of glass and chymical rain. One of the massive jars shattered on the helmet of one officer, who hit the floor again, motionless and bleeding. Vicious shards bounced off the others’ armour. The two militia caught by the deluge were still for a moment, then began to shriek suddenly as the chymicals seeped through their masks and began to attack the soft tissues of their faces.

There was still no gunfire.

Isaac turned again and began to grab more jars, taking a moment to pick strategically, so that the effects of the cascading chymicals were not entirely random. Why don’t they shoot? he thought giddily.

The wounded officers had been pulled out into the street. In their place, a phalanx of heavily armoured officers had entered, bearing iron shields with reinforced glass windows through which they stared. Behind them, Isaac saw two officers getting ready to attack with khepri stingboxes.

They must want us alive! he realized. The stingbox could kill, easily, but it could also not. If deaths were all that were desired, it would have been far easier for Rudgutter to send conventional troops, with flintlocks and crossbows, than such rare agents as humans trained in stingbox.

Isaac hurled a double salvo of trow-iron dust and sanguimorph distillate at the defensive huddle, but the guards were quick, and the jars were shattered with twitching shields. The militia danced to avoid the dangerous gobbets.

Each of the two officers behind the shield-bearers spun their jagged twin flails.