Marc studied the rusted metal frame into which each slat was mounted. The slats were joined to the frame by a screw at each end and although he didn’t have a screwdriver, he reckoned he’d be able to loosen the screw at each end using the director’s hunting knife and then pull them out.

He stumbled as he jumped down off the bin, but he wasn’t hurt and within half a minute he’d grabbed the hunting knife out of the pigskin bag and was trying to get the sharp edge of the blade into a screw head. However, the blade wasn’t really the right width and even when he did manage to get the blade in line to apply some force, the screw didn’t budge because it was held in with thick rust.

Marc groaned, but he was determined and he kept trying. Reaching between the slats for the screw head was an awkward job and after five minutes his shoulder ached and his only achievement was a bloody thumb.

As the knife slipped for the umpteenth time, Marc gave one of the glass slats a final, desperate yank. A chunk of mortar dropped from the gap between the brickwork and the rusty frame holding the slats in place.

Marc studied the gap and noticed that the mortar was badly cracked and crumbled away when he dug it with his thumbnail. He lined the point of the knife up with the hole left behind by the mortar and pushed forwards with a stabbing motion. His reward was a shower of dust, but several more stabs enabled him to make a clear hole between the bricks and the metal. Marc smiled as he pushed the knife into the hole and made the plaster crumble using a sawing motion.

Within a minute he’d cleared a twenty-centimetre gap between frame and wall, but he was making noise, so he decided to stop and make sure he hadn’t caught anyone’s attention. After jumping down and sweeping the loose dust from what was now a filthy set of clothes, he walked back towards the street and peered through the hedge.

A couple of men were trudging up the hill and, judging by their rough appearance, they were heading for the Dormitory Raquel. They probably wouldn’t have heard, but he gave them time to pass before going back to work.

Before long Marc had chipped out all of the mortar along one side of the window. He gave the metal bar holding the slats an experimental knock. The glass shuddered but the mortar at the opposite end snapped away in chunks.