‘A hit!’ cackled Saurizin, shaking a mystifying arrangement of brass screws, rods and lenses at the sky like a geriatric warrior brandishing a sword in victory.

‘A palpable hit with the second discharge, Lord Bayaz!’ Denka could barely contain his delight. ‘One of the stones on the hill was struck directly and destroyed!’

The First of the Magi raised an eyebrow. ‘You talk as if destroying stones was the point of the exercise.’

‘I am sure considerable injury and confusion were inflicted upon the Northmen at the summit as well!’

‘Considerable injury and confusion!’ echoed Saurizin.

‘Fine things to visit upon an enemy,’ said Bayaz. ‘Continue.’

The mood of the two old Adepti sagged. Denka licked his lips. ‘It would be prudent to check the devices for evidence of damage. No one knows what the consequences of discharging them frequently might be—’

‘Then let us find out,’ said Bayaz. ‘Continue.’

The two old men clearly feared carrying on. But a great deal less than they fear the First of the Magi. They scraped their way back towards the tubes where they began to bully their helpless engineers as they themselves had been bullied. And the engineers no doubt will harangue the labourers, and the labourers will whip the mules, and the mules will kick at the dogs, and the dogs will snap at the wasps, and with any luck one of the wasps will sting Bayaz on his fat arse, and thus the righteous wheel of life will be ready to turn once again …

Away to the west a second attempt on the Old Bridge was just petering out, having achieved no more than the first. This time an ill-advised effort had been made to cross the river on rafts. A couple had broken up not long after pushing off, leaving their passengers floundering in the shallows or dragged under by their armour in deeper water. Others were swept off merrily downstream while the men on board flailed pointlessly with their paddles or their hands, arrows plopping around them.

‘Rafts,’ murmured Bayaz, sticking out his chin and scratching absently at his short beard.

‘Rafts,’ murmured Gorst, watching an officer on one furiously brandish his sword at the far bank, about as likely ever to reach it as he was the moon.

There was another thunderous explosion, followed almost immediately by a chorus of gasps, sighs and cheers of wonder from the swelling audience, gathered at the top of the rise in a curious crescent. This time Gorst scarcely flinched. Amazing how quickly the unbearable becomes banal. More smoke issued from the nearest tube, wandering gently up to join the acrid pall already hanging over the experiment.

That weird rumble rolled out again, smoke rising from somewhere across the river to the south. ‘What the hell are they up to?’ muttered Calder. Even standing on the wall, he couldn’t see a thing.

He’d been there all morning, waiting. Pacing up and down, in the drizzle, then the dry. Waiting, every minute an age, with his thoughts darting round and round like a lizard in a jar. Peering to the south and not being able to see a thing, the sounds of combat drifting across the fields in waves, sometimes sounding distant, sometimes worryingly near. But no call for help. Nothing but a few wounded carried past, scant reinforcement for Calder’s wavering nerve.