"Emperor damn them, they must be reading the Tarot wrong. Never trust a psyker, I've always said. It's unnatural."

"As you say, brother-lieutenant." Secretly, brother-sergeant Callaun was not so sure. True, the Dark Angels commanded by Lieutenant Garamanus had been deployed, in full battle-readiness, for more than a week now, and in that time no enemy had emerged, no presence had made itself known, on the jungle moon of Fall. But the small contingent of Astropaths and technoseers had seemed very certain when they informed the Lieutenant of their findings ten days ago, and the Primaris who had joined the Dark Angels on Fall seemed no less sure now. Perhaps they were mistaken, but Callaun felt uneasy whenever he told himself that they would be back with their company in less than a week's time. He felt as if, despite the warm breeze on his face, there was a thunderstorm gathering just beyond the horizon.

"Brother-lieutenant," called the Primaris, looking up from the cards arrayed before him, "the reading has changed."

"Changed how?" demanded Garamanus, without moving any closer to the psyker.

"The primary tokens have shifted their pattern in relation to the quartet of boundary markers," the robed man began, his thin hands pointing to one card after another, seemingly oblivious to the marine's lack of attention.

"Speak in the Emperor's Gothic, man, not in your riddles," interrupted the lieutenant harshly. The Primaris looked up, an offended expression on his face as he seemed to notice the marine's irritation for the first time.

"The Tarot has shifted its emphasis," he explained stiffly. "While the material implications of its patterns are unchanged, the projected course of action laid down by the cards is altering."

"Indeed," said Garamanus with false levity, "I suppose it wants us to go to some other Emperor-forsaken world and stand guard over the native fauna there?"

"Brother-lieutenant, if I may?" asked Callaun. Garamanus shrugged and nodded, stalking off to look down from the command bunker at the miles of forest, in which his force was scattered in a camouflaged defensive formation. Callaun approached the Primaris, who shot a bitter glance at the departing lieutenant.

"I have had cause to rely on the Tarot before," said Callaun, drawing the psyker's attention, "could you form a reading based on the projected path alone? Divine the intended course of action without reference to the situation?"

"I could," replied the Primaris, somewhat mollified by the respect Callaun seemed to pay to the Tarot. He cleared the space before him and began again to deal the hologram-faced cards, placing them in seemingly-random order, drawing from the top, bottom and centre of the deck in his hands, sometimes pausing for a few seconds, at other times moving so fast that the next card was already drawn as the previous one landed on the table.

"I cannot guarantee the accuracy of any tactical decisions based on such a reading," he cautioned. Callaun nodded and waited for the cards to finish falling into their pattern.

"Emperor gives wisdom," muttered the Primaris, when his hands had finally stilled leaving a bizarre mosaic of images and words before him, "servants of Terra..." he fell silent as he interpreted the signs. A frown creased his worn face as he finished the reading.

"What is it?" asked Callaun. The Primaris looked up, bafflement written clearly in his features.

"The reading changes as I read," he said, "it is as if the paths were being rewritten somehow, this is most unusual. The Emperor's message has changed."

"What does it say now?" asked Callaun, feeling the doubt tighten in his stomach again. The Primaris looked back at the pattern, his face becoming pale.

"It says," he croaked, "'save yourselves.'"

"What in the Emperor's almighty name!" bellowed Garamanus from outside, before Callaun had had a chance to reply. The sergeant spun around to see the square of light in the bunker's door fall dark, and rushed outside to find Garamanus staring upwards in horror.

Above them a great machine hovered, slowly casting a false sunset over the forest as it moved. Perhaps it had once been an Imperial craft, but to Callaun's eye it was clearly now the work of chaos. Strings of runes glittered along its hull, giving off a sickly yellow glow of their own, and the giant engines supporting the craft pulsed like living things, letting off deafening howls that sounded as if the vessel's soul was in torment. Even as Callaun's hand instinctively went to the bolter slung over his shoulder a portal opened at the front of the vessel, the metal pulling back from its superstructure like lips drawing back to reveal the fangs inside. From the newly-formed opening emerged hawk-like transports, gliding on the air currents for a moment before diving down towards the forest canopy.

The flyers had already landed by the time Garamanus and his command squad reached the nearest of the defence lines. Through their comm-links they had heard the shouted commands of their brother-sergeants somewhere up ahead, their sharp orders dissolving one by one to incoherent bellowing and screaming. Even now there were handfuls of marines backing out of the trees, firing behind them as they fell back. Many were badly injured, staggering on bloodied legs, clutching their bolters painfully as the weapons' recoil thudded into their broken arms and chests. Many more should have appeared, but of them there was no sign.

"Steady!" roared Garamanus, "Prepare to repel!"

On the tail of his words the first of the attackers emerged from the forest. They wore armour not unlike that of the Dark Angels they pursued, but where the Imperial marines' armour was clean and uniform the renegades were gaudily decorated, the metal plates crossed by leather straps, chains and hooks hanging from them like tinsel on an Emperor's Eve tree. Each one had a simple circle on its helmet, like a slave brand, and on those who wore no helmet the symbol was burned into the flesh of their forehead.

The Dark Angel line erupted in a blast of firepower, throwing the corpses of the chaos marines back into the forest they emerged from. But as each fell another bounded over the body, charging forward, screaming obscene oaths and cries of devotion. On the left flank, closest to the tree-line, the renegades leapt into the trenches, axes and swords slashing about them, the chains on their armour flying in unpredictable arcs, the hooks on them gouging into the bodies around them. One final volley of fire felled several more of the renegades, then the battle was joined in bloody hand to hand combat.

Garamanus and his squad stood steady, pumping shell after shell into the oncoming chaos warriors until their twisted bodies fell at the Dark Angels' feet and they had no choice but to cease fire and continue their work with blades and bayonets. For a moment it seemed the attack was waning, as the losses the renegades had incurred began to take their toll, and each one fought two Dark Angels at once. Then a squad on the right flank collapsed in a chorus of terrible screams, causing a savage cheer to rise from the ranks of the chaos marines. While Garamanus fought three of the renegades single-handedly, Callaun found a moment to seek out the source of the new attack.

She was visible for a moment, among the chaos marines. She wore no armour, it seemed, yet bolter shells were exploding harmlessly against her, leaving no mark on her, barely slowing her advance. Callaun imagined he could taste the metallic hint of powerful psionics in the air, which he had come to recognise from time spent with the Librarians - she was clearly shielded by sorcery. She lashed out with a leather-clad leg, somehow shattering the chestplate of a marine with her kick. From her elbows down she wore a pair of thin, razor-like claws, which had an oily gleam that rose to a blinding white light as she tore them through the bodies of the Dark Angels in her way. Her torso was covered, minimally, by tight leather, like the armour of some medieval Valkyrie - the clothing served only to draw attention to the curves it concealed. She drove a claw through the head of a sergeant, then took a step back and looked towards the press of struggling bodies where Garamanus fought. A savage smile flickered across her face.

Her lips parted, letting out a single clear note that somehow rose above the screaming of the battle. The note split into two, then split again and again, until her lone voice sang a symphony. The air in front of her rippled, forming a wave of half-visible energy that leapt ahead of her, tearing through the warriors in front of her, Dark Angel and renegade alike. All were thrown to the ground, limbs spasming uncontrollably as their internal organs ruptured, their skins splitting in dozens of places to let out gushes of blood that oozed from the joins of their armour. The wave was dissipating by the time it reached Callaun, who fought to escape its path but was knocked backwards by a swinging axe. He screamed as the fading wave touched him, as every muscle in his body cramped, his stomach lurched and he tasted blood and bile on his tongue.

A hand slapped his face, bringing him back from the comforting calm of unconsciousness. He jerked awake, and discovered immediately that he was unable to move. Looking to his side, he saw his wrists speared through by barbed hooks. He was unarmoured - naked, a quick glance confirmed - and bound to a cross of some sort. The arms of the cross seemed to curve downwards, stirring a vague memory of a symbol he had seen in battle, on the armour of the renegades. He craned his aching neck, looking upwards, and saw that the vertical beam was topped by a crescent - he knew now that he had been staked out on the symbol of the traitors' god. As the bitter knowledge passed through his mind, he was aware of a movement in front of him.

He forced his eyes to focus, seeing the sorceress who had led the renegades. She still wore the leathers, but was now surrounded by robes of shimmering scarlet. Her eyes were watching him with cruel amusement, unashamedly taking in the sight of his exposed body.

"Tell me, marine," she said, "are you strong?" The sound of her lyrical voice drew a burst of hatred from Callaun.

"Damn you, strong enough!" he rasped, his throat dry.