For a thousand years, the Sabbat Worlds have been lost to the Imperium, claimed by the dread powers of Chaos. Now, a mighty crusade seeks to return the sector to Imperial rule. And at the forefront of that crusade are Colonel-Commissar Ibram Gaunt and the Tanith First and Only - better known as Gaunt’s Ghosts. Trapped in the grinding trench warfare of Fortis Binary, the Ghosts find themselves drawn into a conspiracy to assassinate the crusade’s leader, Warmaster Macaroth.

The eldar are an ancient race whose mode of war blends spirituality with a unique mastery of technology. In times of need, their entire race will rouse to war, led by terrifying, almost mythological figures - the phoenix lords, immortal beings that embody the warrior nature of the eldar. When a burgeoning ork empire starts to pose a threat to the eldar peoples, Jain Zar travels to the craftworld Ulthwé to warn them of the danger.

The Aeronautica Imperialis are the masters of the skies in the 41st millennium, waging wars of breakneck aerial combat where only skill stands between victory and death. Flight Commander Lucille von Shard is an ace, a living exemplar of what it means to fly in the name of the Emperor… or so Propagandist Kile Simlex is told. Braving the foetid waters of Bacchus and its rampaging greenskin hordes, Simlex is tasked with producing a cinema-pict portraying Shard as an Imperial hero. Shortly after his arrival planetside, however, he discovers the war effort is in shambles.

Newly promoted to the captaincy of the Ultramarines Fourth Company, Uriel Ventris leads his warriors to the world of Pavonis, where vicious alien raiders are bringing death and destruction. As Pavonis descends into political turmoil, Uriel and his warriors must battle the xenos as they unravel a plot to unleash an ancient evil buried deep beneath the world - the mysterious and deadly Nightbringer.

For Ianthe, war is all too familiar. A former soldier in the Astra Militarum, she now serves Inquisitor Covenant as an agent of the Throne. Her first mission sees her investigating a cult called the Children of Eternity. Falling foul of the local Enforcers, Ianthe soon learns that war in the shadows is seldom straightforward and that the local, angry law-keepers are the least of her troubles.

For nearly 10 millennia, the Crimson Fists waged war against the enemies of mankind from their home planet of Rynn's World. And then, in one cataclysmic event, Rynn's World fell, despoiled by the hordes of the orks. Six months later, Chapter Master Pedro Kantor leads the shattered remnants of his Space Marines in pursuit of a force of greenskins still clinging to life in the mountains of the devastated world.

When his body is hideously damaged in an enemy attack, it looks as though Inquisitor Gideon Ravenor's promising career would be abruptly brought short. Now, encased in a life support sytem that keeps him alive but forever cuts him off from the physical world, Ravenor utilises his formidable mental powers to continue his investigations. Along with his retinue of warriors and assassins, Gideon Ravenor fights to protect an Imperium he can no longer see, hear or feel.

Under almost constant besiegement by the hosts pouring from the Eye of Terror, Cadia acts as a bulwark against tyranny and death. Its fortresses and armies have held back the hordes of Chaos for centuries, but that grim defiance is about to reach its end. As Abaddon's Thirteenth Black Crusade batters Cadia's defences, and armies of the Imperium flock to reinforce this crucial world, a terrible ritual long in the making comes to fruition and the delicate balance of this brutal war shifts.

In the age of the Dark Imperium, Primarch Guilliman’s Primaris Ultramarines are a shining beacon in the darkness of war. On the Imperial Hive World of Ikara IX, Chaplain Kastor and Apothecary Polixis, brothers in blood as well as in battle, stand firm against the endless Greenskin horde. But a threat is looming. An invasion like no other assaults the broken city of Shebat, as the crazed warlord Urgork arrives to lay waste to the Imperial forces and capture a Primaris Marine for his own twisted ends.

There are those in the great expanse of the galaxy that seek profit wherever it is to be found: the deal makers, the opportunists and explorers – the Rogue Traders. Granted power by an ancient charter, sanctioned by the Emperor Himself, these scoundrels, entrepreneurs and adventurers roam the galaxy in search of fortune and glory. None perhaps are as hungry for these twin vices as Janus Draik.

Lord Azariel, Head of the Navigator House Brobantis is dead. His widow and murderer, the Lady Chettamandey, stands to inherit his power and influence. Her plans for ascension are curtailed when she’s drawn into a dark world of ritual killings and cult murders. With planets being dragged into the warp seemingly at a whim, the threat to Chettamandey’s legacy is dire, and only she can avert potential disaster.

After seven long years of conflict, the Horus Heresy nears its end. But now, as the Warmaster Horus marches on Terra to rip his father from the Throne, the seat of the arch-traitor’s power lies empty. Cthonia, a world once dominated by brutal murder-gangs, is occupied by the Emperor’s praetorians—the indomitable Imperial Fists. For the Sons of Horus, this outrage demands a reckoning.

The Battle Titans of the Adeptus Titanicus are towering war engines, striding to war as holy effigies of the Omnissiah. Greatest of all are the mighty Warlord Titans, their weapons bringing righteous death to alien and heretic alike. Still reeling from a near disastrous battle against tyranids, the Pallidus Morr demi-legio is assigned to a new warzone, a nearby forge world which has fallen under the sway of Chaos.

By the blessing of the Omnissiah was the Mars Triumphant born – from the forges of the Adeptus Mechanicus, the mighty Baneblade super-heavy battle tank comes to bring death and destruction to the foes of the Imperium. As part of the Paragonian 7th Company, Honoured Lieutenant Marken Cortein Lo Bannick commands the venerable war machine in a bitter war against the orks in the Kalidar system. As the campaign grinds on it begins to take its toll upon his crew, and old clan prejudices from the regiment's home world arise once more. In a war which cannot be won by force of arms alone.

The Horus Heresy is a civil war on a scale the likes of which the galaxy has never seen before. After the Great Crusade united the disparate worlds of humanity, the very warriors who made it possible turned on each other and tore it apart. The Siege of Terra looms, and the fate of the galaxy balances on a razor's edge.