Here in the mangrove the pungency of decayed vegetation combined with the odour of human waste and the sweet stench of rotting flesh. Cato covered his nose with his hand and swallowed the bile rising in his throat. At least the darkness concealed the detritus floating about his knees. Ahead of him, beyond the broad dark bulk of Macro, he could just see the tall figure of Prasutagus leading the way through the rushes. The stalks rustled as the Briton slowly waded from one coppice stake to the next. Most were still in place, and Prasutagus had lost his way only once, suddenly splashing down into deeper water with a sharp cry. All three had frozen, ears straining for any indication of alarm from the dark mass of the Druids’ island above the slopping of the water. When the disturbed water had stilled again, Prasutagus gently eased himself back onto more solid ground and flashed a dim grin at the centurion.

‘Long time gone before I here,’ he whispered.

‘All right.’ Macro said softly. ‘Now just keep your mouth shut and your mind on the job.’

‘Huh?’

‘Get a fucking move on.’

‘Oh. Sa!’

At length they emerged from the rushes and Prasutagus halted. The island still seemed some distance away but Cato noted that the rushes reached most closely towards it at this point and could see why Prasutagus had picked this route for his night-time assignations. The open water contained no more stakes to guide them. Prasutagus was shifting his position and staring hard at the island. Following his gaze, Cato could see two dead pine trunks standing out above the rest of the trees on the island. They were so close together that from certain angles they looked like a single trunk, and Cato realised that their alignment was how Prasutagus guided himself across the open water to the island. The Icenian shuffled to his left and then motioned to the others to follow him.

Moving slowly, the water gently swirling around their knees, the small party headed across towards the dark foreboding shadow of the Druids’ island.

The stench slackened as they moved further out from the rushes. Cato allowed himself a few deep breaths as he carefully followed in line behind the others. Underfoot, the bottom felt strangely soft and yielding, with the occasional firmness of a branch. For a moment he wondered how Prasutagus could possibly have constructed this underwater walkway. Then he decided it must just be the tangled accumulation of dead and fallen matter which the Briton must have found by chance, and put to good use. Cato smiled to himself. Good use, maybe. But it had caused him to be expelled from the order of the Dark Moon.