He watched a Techmarine wiring the bridge supports for destruction. Melta charges would blast the bridge to pieces, denying the traitors any way of moving their armoured units across the river and flanking the Imperial attack. Uriel knew that the same scene was being repeated up and down the enormous gorge as other Ultramarine detachments prepared to destroy their own targets. He scooped up his helmet and marched towards a mud-stained Techmarine hauling himself over the parapet and unwinding a long length of cable from his equipment pack. The man looked up as he heard Uriel approach and nodded respectfully.

'I suppose you're going to tell me to hurry up,' he grumbled, bending awkwardly to hook the cable into a battery pack.

'Not at all, Sevano. As though I would rush the work of a master craftsman like yourself.'

Sevano Tomasin glowered at Uriel, searching his face for any trace of sarcasm. Finding none, the Techmarine nodded as he continued wiring the explosives, moving with a lopsided, mechanical gait as born his legs and right arm were heavier, bionic replacements.

The apothecaries had grafted these on after recovering his body from the interior of a wrecked Land Raider on Ichar IV - after a rampaging carnifex had ripped it apart. The horrifying creature's bio-plasma had flooded the interior of the armoured fighting vehicle, detonating its ammo spectacularly. The carnifex was killed in the blast, but the explosion sheared Tomasin to the bone and, rather than lose his centuries of wisdom, the Chapter's artisans had designed a completely new, artificial body around the bloody rags of his remains.

'How long until you and the servitors are finished?' asked Uriel.

Tomasin wiped the mud from his face and glanced up the length of the bridge. 'Another hour, Ventris. Possibly less if this damned rain would ease up and I didn't have to stop to talk to you.'

Uriel bit back a retort and turned away, leaving the Techmarine to his work and striding to the nearest gun nest. Captain Idaeus was sitting on the sandbags and speaking animatedly into the vox-com.

'Well make sure, damn you!' he snapped. 'I don't want to be left sitting here facing half the rebel army with only thirty men.'

Idaeus listened to the words that only he could hear through the comm-bead in his ear and cursed, snapping the vox unit back to his belt.

'Trouble?' asked Uriel.

'Maybe,' sighed Idaeus. 'Orbital surveyors on the Vae Victus say they think they detected something large moving through the jungle in our direction, but this damned weather's interfering with the auguries and they can't bring them on-line again. It's probably nothing.'

'You don't sound too convinced.'

'I'm not,' admitted Idaeus. 'If the Night Lords are on this world, then this is just the kind of thing they would try.'

'I have our scouts watching the approaches to the bridge. Nothing is going to get close without us knowing about it.'

'Good. How is Tomasin getting on?'

'There's a lot of bridge to blow, captain, but Tomasin thinks he'll have it done within the hour. I believe he will have it rigged sooner though.'

Idaeus nodded and rose to his feet, staring into the mist and rain shrouded hills on the enemy side of the bridge. His face creased in a frown and Uriel followed his gaze. Dusk was fast approaching and with luck they would be on their way to rejoin the main assault on Mercia before nightfall.

'Something wrong?'

'I'm not sure. Every time I look across the bridge I get a bad feeling.'

'A bad feeling?'

'Aye, like someone is watching us,' whispered Idaeus.

Uriel checked his vox-com. 'The scouts haven't reported anything.'

Idaeus shook his head. 'No, this is more like instinct. This whole place feels wrong somehow. I can't describe it.'

Uriel was puzzled. Idaeus was a man he trusted implicitly, they had fought and bled together for over fifty years, forming a bond of friendship that Uriel found all too rarely. Yet he could never claim to truly understand Idaeus. The captain relied on instinct and feelings more than the holy Codex Astartes, that great work of military thinking penned ten thousand years ago by their own Primarch, Roboute Guilliman.

The Codex formed the basis of virtually every Space Marine Chapter's tactical doctrine and laid the foundations for the military might of the entire Imperium. Its words were sanctified by the Emperor himself and the Ultramarines had not deviated from its teachings since it had been written following the dark days of the Horus Heresy.

But Idaeus tended to regard the wisdom of the Codex as advice rather than holy instruction and this was a constant source of amazement to Uriel. He had been Idaeus's second-in-command for nearly thirty years and, despite the captain's successes, Uriel still found it hard to accept his methods.

'I want to go and check those hills,' said Idaeus suddenly.

Uriel sighed and pointed out, 'The scouts will inform us of anything that approaches.'

'I know, and I have every faith in them. I just need to see for myself. Come on, let's go and take a look.'

Uriel took out his vox unit, informing the scouts they would be approaching from the rear and followed Idaeus as he strode purposefully to the end of the bridge. They passed the far bunker, the one the rebels should have occupied, noting the glint of bolters from within. The two Space Marines marched up the wide road that led into the high hills either side of the gorge and for the next thirty minutes inspected the locations Uriel had deployed the scouts to watch from. The rain deadened sounds and kept visibility low and there was enough tree cover to almost completely obscure the jungle floor. There could be an army out there and they wouldn't see it until it was right on top of them.

'Satisfied?' asked Uriel.

Idaeus nodded, but did not reply and together they began the trek back to the far bunker where they could see Sevano Tomasin.

The warning came just as the first artillery shell screamed overhead.

Almost as soon as Uriel heard the incoming shell, the comm-net exploded with voices: reports of artillery flashes in the distance and multiple sightings of armoured personnel carriers and tanks. A blinding explosion in the centre of the bridge, followed by half a dozen more in quick succession, split the dusk apart. Uriel shouted as he saw the servitors and two Space Marines blasted from the bridge, tumbling downwards to the rocks below.

The two officers sprinted down towards the bridge.

Uriel dialled into the vox-net of the Scouts as he ran and yelled, 'Scout team Alpha! Where in the warp did they come from? Report!'

'Contacts at three kilometres and closing, sergeant! The rain held down the dust, we couldn't see them through the dead ground.'

'Understood,' snapped Uriel, cursing the weather. 'What can you see?'

'Can't get an accurate count, but it looks like a battalion-sized assault. Chimeras mainly, but there's a lot of heavy armour mixed in - Leman Russ, Griffons and Hellhounds.'

Uriel swore and exchanged glances with Idaeus. If the scouts were correct, they were facing in excess of a thousand men with artillery and armoured support. Both knew that this must be the contact the auguries on the Vae Victus had detected then lost. They had to get everyone back across the bridge and blow it right now.

'Stay as long as you can Alpha and keep reporting, then get back here!'

'Aye, sir,' responded the scout and signed off.

More shells dropped on the bridge, the echoes of their detonations deafening in the enclosed gorge. Each blast threw up chunks of the roadway and vast geysers of rainwater. Some were air-bursting above the bridge, showering the roadway with deadly fragments.

Uriel recognised the distinctive whine of Griffon mortar shells and gave thanks to Guilliman that the PDF obviously did not have access to the heavier artillery pieces of the Imperial Guard.