‘Let me show you, if I may, sir.’ Perkins did not wait for a reply but made his way through the breach and crouched down just inside the ruined masonry. He turned and gestured to Arthur to keep his head down. Arthur crouched beside him and quickly glanced round the interior of the fortress’s first wall. A cobbled track ran between the two walls, and to its side there was a cliff of perhaps twenty feet in height before the foundations of the second wall rose up. The cliff was a good fifty feet from the breach. Perkins coughed and smiled apologetically. ‘Caught a bit of a cold in all this damp, sir. Anyway, as you can see, there’s open ground between us and the cliff. In order to mine the second wall we will need to cut into that rock and tunnel up towards the foundations. It’s going to be a tough job.’

‘But you can do it?’

‘Given time, sir. Yes.’

‘Time is something we are a little short of, Perkins. My scouts to the north report that a French army is gathering to relieve Burgos within the month. The latest word from Madrid is that Soult is marching to join Joseph. When that happens they will make for Madrid. We have to take Burgos as soon as possible and join forces with Hill if we are to hold the centre of Spain. Do you understand?’

‘Aye, sir, I do. We will carry out our duty as swiftly as we can, but before we can start mining we have to get the lads across the open ground. A trench is no good because the Frogs have the ground covered by the bastion to our right, and the angle of the wall to the left there. At the moment the Portuguese boys have the wall covered’ - he nodded towards the brown-uniformed men crouching amid the rocks at the base of the cliff on either side of the breach - ‘but to get men and equipment up to the cliff we are going to have to build a covered gallery across the open ground. Dangerous and time-consuming work, sir.’

‘I see. How long will it take?’

Perkins pursed his lips. ‘Two days to erect the gallery. Two weeks to tunnel up through the rock, a day to prepare the mine, and then it’s up to the infantry to storm the fortress, sir.’

‘Two and a half weeks, then,’Arthur mused.‘That’s cutting it fine. Do whatever you can to speed things up, Perkins.’

‘Aye, sir. I’ve had the necessary tools brought forward and I’ll set the lads to work as soon as the breach is cleared.’

‘Very well.’Arthur clapped him on the shoulder.‘Keep me informed.’