He turned back to Metellus. ‘Take my arm, and hold it tight.’

With Metellus anchoring him to the bank Cato took a tentative step onto the cracked surface of the mud and at once his foot sank in several inches. He leaned forward again, fingers in contact with the wavering end of the spear shaft. He clenched his fingers around the hard wood and began to pull. Along the length of the spear he could see Proculus’ knuckles, white with the strain of clutching on to this slender lifeline. Beyond that the wide terrified eyes fixed on the centurion.

‘Hold on!’ Cato grunted through his teeth.’Hold on, man!’

For a moment he felt the spear shift towards him, and then there was no more movement, no matter how hard he strained to pull Proculus back to the bank. He closed his eyes and made one last, intense effort, to no avail, and relaxed his muscles.

‘This isn’t working.’ Cato glanced round quickly and snapped out some fresh orders. ‘We need some matting. Cut some branches. Toss them on the mud. Do it!’

As he and the others pulled their daggers out and began to saw at the slender branches of the gorse, Proculus looked about him with a growing sense of horror. The mud sucked him down steadily and was now oozing around his waist. Beyond him the deer, still in death, was sinking more slowly, and already the head was hidden from sight, only a stiff ear breaking the surface of the oily water on the surface of the mud.

‘Get me out of here!’ Proculus pushed down at the mud, then tried to sweep it away from his waist.

‘Keep still, you fool!’ Cato hissed. ‘You’re only making yourself sink faster. Keep still!’

The gorse branches were tougher than Cato had expected and still not one length had been cut free. He drew his knife arm back and stamped down on the sinewy white pulp he had tried to saw through, but the branch just gave way beneath him and did not snap.

‘Shit!’

Cato resumed sawing, with increased desperation as he glanced over at Proculus, now up to his chest.

‘There!’ One of the men grunted, and threw a branch down on to the mud by the bank, and immediately began to saw at another.

‘For fuck’s sake!’ Proculus cried out. ‘Faster, you bastards! Faster!’

The dagger cut through the branch by Cato’s hand and he turned and tossed it down on top of the first one, glancing across towards the trapped legionary.

‘Oh no . . .’ Cato whispered. Only the man’s head and shoulders were above the surface now, his arms stretched out across the mud towards his comrades. Proculus still held the spear tightly in his right hand. With a gurgle he sank a little further and some of the oily water spilt into his mouth.

‘Oh, shit!’ Proculus gurgled. ‘Save me!’