For the first hour of the night the enemy continued to pile their combustibles against the fort and their slingers were watchful for any sign of movement along the wall, loosing off their deadly shot at any Roman who dared to show himself. Macro risked the occasional glance to follow the enemy’s progress and for a time he saw Caratacus and his shield bearer striding behind the shelters, surveying the work of his men. At length Caratacus called down to the camp and a short while later small flames flickered as they approached the fort and Macro saw teams of men scurry up to the piled wood with buckets. The sharp smell of pitch reached his nose and he knew that time was running out for the garrison. Then the stench of acrid smoke caught in his throat. The crackling sound of burning timber spread along the wall as one pile of wood after another was ignited. The rim of the parapet and hoardings were sharply defined against the loom of the fire burning at the foot of the gatehouse. A yellow tongue of fire licked up into Macro’s field of vision.

‘Shit. Shit. Shit,’ he hissed through clenched teeth.

There was a cry of alarm from below. ‘There’s smoke in here! Get out! Get out!’

Macro turned and saw that the handful of men with him on the tower were looking at him anxiously. He smiled calmly. ‘Time to move, lads. I don’t fancy being a burned offering to some fucking barbarian god.’

The legionaries scrambled over to the ladder and descended out of sight. As Macro rose to follow suit, he felt the stinging heat of the flames rising up in front of the gatehouse. He swung himself on to the ladder and stepped down the rungs, immediately aware of the smoke starting to fill the watchroom. The doors leading out on to the walkway behind the wall were both open and there was a light breeze as air was sucked inside to feed the flames. Thin slivers of brilliant light were visible through the chinks in the gatehouse’s timbers, and the roar of flames and crackle of burning wood filled Macro’s ears. He breathed in and abruptly doubled over, coughing violently, and his eyes smarted. Making for the nearest door, he emerged from the gatehouse and staggered a short distance along the wall before crouching down.

It took a moment to clear his lungs and blink away the tears from his stinging eyes before he could take in the situation. Several fires were burning along the length of the wall facing the slope down to the parade ground, the biggest of which was the blaze raging up the front of the gatehouse.

‘Sir!’

Macro looked round to see Centurion Petillius standing below him at the foot of the rampart, his face lit by the flames. Petillius was pointing towards the gatehouse. ‘Shall I get one of the centuries to fetch water?’