At level fifty-three there was an access gate that had been forced open. It should have been locked from the inside, but someone had been careless, and carelessness was costing the traitors lives.

Minka pushed through. The tunnel smelt of damp. The arched ceiling was lined with sheets of corrugated iron and held in place with iron arches all bolted to one another, forming regular struts across the floor. The corridor went straight into the mountainside. Every fifty yards there was another flight of steep stairs. At the end they came to a ventilation door, and the first dead bodies. Three of the locals were lying in pools of their own blood.

Minka avoided the blood.

She pressed herself against the wall and came out into a wide chamber with a series of armoured doorways along the inner side. They had stencilled numbers on the front. The closest one was labelled ‘57’.

Minka’s first experience of battle had been the fight for her home fortress of Kasr Myrak. City fights were deadly things. They strained the nerves and they killed the weak at a relentless rate, but for Minka, fighting in cramped conditions was in some ways just like coming home.

The magazine was located on the next floor down.

A team of labourers had been working to bring out bombard shells and they barely knew what happened as Minka and Blanchez strode in and gunned them down.

From the lift chamber, a series of arched chambers led away, one after another, each with their own heavy blast doors. The nearest door was open and an artillery trolley stood by the lift, already loaded with bombard shells. They were fearsome things, each weighing twice as much as a man.

Blanchez grabbed a ten-pound shell and quickly wrapped the detonator wires around it.

‘I’ve got the mother of all bombs here,’ she hissed as she spooled out the detonator wires, ‘but I need five minutes.’

‘Get the other blast doors open!’ Minka shouted as she stood at the mouth of the tunnel. She could hear footsteps and braced herself as a response team of Swabians appeared at the end of the corridor.

She fired off a salvo of shots down its length. The bark of the bolt pistol drove the enemy back. She felt a few of the Swabian shots hiss past her cheek. Too close, she decided and tossed another frag grenade down the corridor, bouncing it from one wall to another.

After a few minutes she called out, ‘They’re coming again.’

Blanchez had a clasp in her mouth as she screwed the last wire into place.

‘Nearly done,’ she mumbled.

There had to be twenty of them. A firefight erupted. Las-bolts flashed up the access tunnel towards them. One hit a lumen above Yedrin’s head. The glass exploded with a shower of sparks and he ducked back, tossing a frag grenade down the corridor just to give himself some time.