The general let slip an oath and his horse raised its head in alarm from the nearby copse where it had been tethered. The wagon was lost then, that much was evident, and the chest itself was too heavy to carry back to the last ship waiting at anchor. For security’s sake the key to the chest had remained with the quartermaster, now well out to sea, and the chest was so constructed as to make it impossible to open without the right tools.

‘What now, sir?’ the centurion asked.

The general looked long and hard at the chest, in silence. There was nothing he could do — nothing at all. Wagon, chest and contents were not going to move. For a moment he dared not contemplate that, since the loss of the chest would set his political plans back by a year at least. In that agonising moment of indecision a war horn blew close at hand. With terrified expressions, the legionaries started to wade back towards their weapons lying on the track.

‘Stay where you bloody are!’ the general roared. ‘I haven’t ordered you to move!’

The legionaries paused, even with the enemy close at hand, such was the depth of their awe and respect for their commander. With a last look at the chest, the general nodded as he made his decision.

‘Centurion, get rid of the wagon.’

‘Sir?’

‘It’ll have to stay here until we return next summer. Drag it a little further in so it sinks, mark the spot and then get back to the beach as fast as you can. I’ll have them hold a tender ready for you.’

‘Yes, sir.’

The general slapped his thigh angrily, then turned to mount his horse and set off back through the marsh towards the beach. Behind him came another burst from the war horn and the sound of swords clashing as the cavalry scouts fought it out with the vanguard of Caswollan’s army. From the moment the Romans had landed, to their present flight back to Gaul, Caswollan’s men had dogged them every step of the way, harrying stragglers and foragers day and night, and showing no mercy to the invaders.

‘Right, lads!’ the centurion bellowed. ‘One last heave … Get your shoulders to the wagon. Ready now… Heave!’

Slowly the wagon sank further into the mire; dark brown marsh water flowing up through the seams in the bed of the wagon and rising up the sides of the chest.

‘Come on! Heave!’

With a last combined thrust the men eased the wagon further into the marsh and, with a soft gurgling plop, the wagon disappeared beneath the dark water leaving a faint swirl rippling across the oily surface, broken only by the long wagon shaft.

‘That’s it, lads. Back to the ship. Smartly does it.’

The legionaries waded ashore and snatched up their shields and spears while the centurion hurriedly sketched a map of the location on the wax tablet hanging from his shoulder. When he was done, he snapped the tablet shut and joined his men. But before the column could move off a sudden pounding of hoofbeats on the track caused his men to turn, wide-eyed and afraid. Moments later a handful of cavalry scouts burst out of the mist and galloped by the infantry. One scout leaned forward across his horse’s neck which ran with blood from a gaping wound in the man’s side. Then they were gone.