This Journal Tactica explores how Saturnine technology emerged during the early days of expansion, and how Vulkan—ever the artisan—sought to rekindle these designs for the Legiones Astartes. We also get a glimpse at how each of the other 17 Legions reacted to his “gift,” in the tense years before the galaxy fell into civil war.

But this isn’t just a lore drop—it’s packed with playable content:

• Three new units, including Saturnine-equipped Centurions, upgraded Command Squads, and a brutal daemon-infused Terminator unit unique to the Word Bearers
• A new Prosperine Arcana for the Thousand Sons, unlocking even more psychic potential
• Two new detachments that are usable by Astartes Legion Armies.
• New Legendary & Onslaught Missions

The result is a focused expansion that blends deep narrative with tactical opportunity—an ideal pickup for Salamanders players, Saturnine lore fans, or anyone looking to add a bit more bite to their Heresy games.

New Detachments

This tome introduces several new Astartes detachment options for building your armies. Each one brings fresh tactical opportunities—but they don’t come without strings attached. These aren’t plug-and-play formations; they come with specific requirements you’ll need to meet. If you’re ready to jump through a few hoops, though, you’ll find some powerful new ways to shape your force.

Linebreaker Echelon ( Apex Detachment )

Slots: This detachment is comprised of 2 Heavy Assault slots ( one of which is a prime slot ), 1 Retinue slot, and 1 War Machine slot.

Requirements: When selecting this detachment, the controlling player must choose one of the following keywords: Saturnine, Tartaros, or Cataphractii. Both Heavy Assault and Retinue slots must be filled with units whose names include the selected keyword.

This new Astartes detachment is tailor-made for Terminator-led strike forces. It gives you access to two Heavy Assault units—one eligible as a Prime—alongside a dedicated Retinue and a heavy War Machine. It’s a perfect fit for anyone building from the Saturnine Box Set, letting you field both Terminator squads and your Saturnine-pattern Dreadnought in a single, cohesive detachment.

Maelstrom Sentry Battery ( Auxiliary Detachment )

Slots: This detachment is comprised of 2 Support Slots and 3 Recon Slots.

Requirements: This detachment may only be selected if the controlling player includes a Master of Signals in a Command Force Organization slot. Additionally, the unit options are restricted as follows:

• Support slots may only be filled with Araknae Quad Accelerator Platform units
• Recon slots may only be filled with Tarantula Battery units

This is a specialized auxiliary detachment built around static firepower and battlefield control. It’s ideal for players who want to represent entrenched defensive positions, fortified kill-zones, or automated strongpoints—especially when coordinating with a Master of Signals. While limited in flexibility, it adds flavorful and thematic support to a larger force structure.

New Units

There are several new units available, mostly for the Astartes legion, but there is a new unit specifically for the Word Bearers Hereticus legion.

Centurion in Saturnine Terminator Armor ( 150 points )

Unit Composition: 1 Centurion in Saturnine Terminator Armor.

This new command option is perfect for players leaning into the Saturnine theme, offering both resilience and leadership in one hardened shell. You get all the benefits of fielding a standard Centurion—most notably Officer of the Line (2)—but wrapped in the brutal durability of Saturnine-pattern warplate.

The Centurion’s wargear matches that of a standard Saturnine Terminator, giving you solid offensive flexibility. It also comes equipped with a unique piece of default equipment: the Saturnine Teleport Synchronizer. This wargear grants the Centurion the Deep Strike special rule, but only if another friendly unit with the Saturnine Teleportation Transponder is also present on the battlefield.

In short: it’s a command choice that hits like a hammer and drops in like one, too.

Saturnine Command Squad ( 160 points )

Unit Composition: 1 Saturnine Chosen Champion and 1 Saturnine Chosen. ( may include up to 4 additional Saturnine Chosen at +60 points per model )

The Saturnine Command Squad offers a premium—but powerful—command option for armies focused on Saturnine-pattern Terminators. While it comes at a steep cost, it brings considerable flexibility and firepower, and serves as a perfect companion unit for your Centurion or Praetor.

This squad uses all the core rules of standard Saturnine Terminators but includes the Saturnine Teleport Synchronizer as standard, allowing the unit to Deep Strike independently—no need to attach them to a Praetor with teleportation gear.

You can equip the squad with any of the standard Saturnine arsenal, including:

• Plasma Bombard
• Twin Heavy Disintegrator
• Concussion Hammer
• Saturnine War Axe

Most excitingly, the unit also introduces a new melee-focused build: the Paired Saturnine Disruption Fists. These grant +1 to Attacks, AP 2, and a Damage characteristic of 3, finally delivering a dedicated close-combat option for Saturnine elites.

If you’re looking to anchor an elite spearhead with a mix of raw firepower, teleportation flexibility, and brutal melee options, the Saturnine Command Squad delivers.

Phraetus Anointed Conclave ( 240 points )

Unit Composition: 1 Phraetus Disciple and 2 Phraetus Anointed ( may inlcude up to 2 additional Phraetus Anointed at + 65 points per model. )

This dark reflection of the Saturnine Command Squad is available only to the Word Bearers, blending brutal Terminator warplate with the twisted gifts of the warp. The Phraetus Anointed Conclave carries all the same deadly weapon options as its loyalist counterparts—including the Saturnine War Axe, Concussion Hammer, Plasma Bombard, Twin Heavy Disintegrator, and Paired Concussion Fists—but with a distinctly corrupted edge.

The Phraetus Disciple may be upgraded with a Saturnine Teleportation Transponder, allowing the entire unit to gain Deep Strike, letting these daemon-infused brutes manifest anywhere on the battlefield with terrifying precision.

What truly sets the Conclave apart is their default wargear: the Warpfire Mantle. When the unit is targeted by ranged attacks, reality itself lashes out. Every time they are hit by a shooting attack (regardless of whether wounds are suffered), all enemy units within 8” of the Conclave must roll a die. On a success, they suffer D3 automatic wounds—AP 2, 1 Damage each, and no saves of any kind may be taken.

This makes the Conclave not just hard-hitting in melee, but punishing to attack at range. Their presence on the battlefield is a psychic hazard—and a narrative centerpiece for any Word Bearers force.

New Arcana

The Forges of Saturn introduces a new Prosperine Arcana exclusive to the Thousand Sons: the Osiraean Arcana. This upgrade grants access to two new psychic powers and confers the Osiraean trait to eligible units.

• Praetor in Saturnine Terminator Armor
• Centurion
• Saturnine Terminator Command Squad
• Saturnine Terminator Squad
• Any unit entirely composed of models with the Walker Type.

Psychometry ( Psychic Power, Blessing )

This psychic power can be used in the shooting phase to decrease the value of the Overload(X) special rule on a unit's weapons.

Machine Empathy

This psychic power can be used in the start phase to restore a single wound to a unit.

New Missions

One of the real highlights of The Forges of Saturn is its mission content—four new battle scenarios that blend rich lore with dynamic gameplay. These aren’t just filler. They’re well-crafted narrative missions that give players the tools to recreate brutal engagements from the Heresy, or to drop their own Legions into the meat grinder of war-torn Saturnian soil.

Legendary Mission – Ignis Sector Assault

The centerpiece of the mission section is a Legendary Mission that lets you reenact the Salamanders’ assault on entrenched Iron Warriors positions during the Isstvan V campaign. This isn’t just another “line up and charge” scenario—it’s a layered assault with multiple deployment zones, rules for preliminary bombardments, defensive reinforcements, and special spearhead sectors that reward the use of Saturnine-pattern units.

While the mission doesn’t require any specific Legions, two attacker deployment zones are flagged for Saturnine-equipped forces—making it a perfect excuse to field your new Centurions, Command Squads, or Word Bearer nightmares in full regalia. The attacker must punch through hardened defenses while managing waves of resistance, and the result is a cinematic, grindhouse slugfest that feels straight out of a Black Library novel.

Three Onslaught Missions – Tactical Pressure Cookers

In addition to the Legendary setup, the book includes three Onslaught Missions—asymmetrical scenarios built around one side digging in and the other mounting a relentless offensive. These missions introduce a clever twist: the defender’s Line(X) units are stripped of their scoring status, reclassified as Vanguard, while objectives slowly advance toward the defender’s zone as the game progresses.

This mechanic—advancing objectives—is what sets these missions apart. Not only do the objectives move forward, but they become worth more points the closer they get to the defender’s lines. This creates constant tension between offense and defense, encouraging mobile lists, strategic redeployment, and brutal mid-board brawls.

Here’s a quick overview:

• Line Advance: A classic long-edge deployment where objectives push steadily into the defender’s territory. Each one can move twice during the game, meaning even a strong early lead can be overturned if the attacker maintains pressure.
• Breakthrough: Featuring a “U” shaped objective spread—two objectives begin in each player’s half. The attacker gets an added benefit here: they can bring reinforcements in from either short edge of the board, creating flanking threats that defenders will struggle to contain.
• Dawn Raid: Corner deployments and a single objective deep in the defender’s zone define this one. The defender sets up first, but the attacker has a 50/50 chance to seize the initiative—turning what seems like a solid defense into a sudden scramble. This mission is all about quick reaction and brutal trades.

These missions feel tailor-made for campaign and narrative play, offering fresh strategic challenges while staying firmly rooted in the lore. Whether you’re leading a loyalist hammer strike or holding the line for the Warmaster, there’s something in The Forges of Saturn to test your mettle.

New Lore - The Phoebian Accord

The story begins on Phoebe, one of Saturn’s moons and home to a group of tech-adepts who stood apart from the Martian Mechanicum. Operating under their own codes and principles, these independent forge masters forged a pact with the Emperor himself—the Phoebian Accord. In exchange for the Imperium’s protection during the Great Crusade, they offered something remarkable: the development of Saturnine-pattern Terminator armor.

Unlike the more common warplate that would come to dominate the Legiones Astartes, Saturnine armor was complex, temperamental, and costly to maintain. Its bulk and intricacy made it a logistical nightmare for many Legions, and over time, it fell out of favor—except with one: Vulkan, Primarch of the Salamanders.

Vulkan championed the armor’s potential, even as his brother-Legions moved on. Through sheer will and collaboration with Martian adepts, he helped revise and modernize the Saturnine pattern, making it more accessible for mass production and repair across the Legions.

The Journal goes on to explore how this distinct armor saw use—both heroic and horrific—throughout the Legiones Astartes. The Dark Angels’ Naufragia, the Blood Angels haunted by the shadows of Signus, and the Deliverers of the Raven Guard are all depicted incorporating Saturnine plate into their ranks. Even among the traitors, the armor found twisted expression: Emperor’s Children adapted it to heighten sensation, World Eaters used it to intensify their pain-driven fury, and Sons of Horus folded it into their elite Justaerin formations.

Interestingly, these darker uses often emerge after the Isstvan V Dropsite Massacre, and the Journal notes that by that time, sightings of Saturnine plate among the Traitor Legions had already begun to decline—hinting at deeper narrative and strategic shifts within the war.

Finally, the book sets the stage for its Legendary Mission by expanding on Vulkan’s foresight during the Isstvan campaign. His stockpiling and deployment of Saturnine armor becomes a key part of a contingency plan—a tragic but compelling thread woven into one of the Heresy’s most pivotal battles. It’s a fresh perspective on a familiar moment, offering new depth to a conflict many fans know well.

Final Thoughts

The Forges of Saturn is exactly the kind of supplement that keeps Horus Heresy 3.0 feeling alive, experimental, and connected to the heart of its narrative roots. It blends crunchy, flavorful rules with deep lore dives, all while introducing new ways to build and theme your armies—especially if you’re a Salamanders or Word Bearers player, or simply a fan of the Saturnine aesthetic.

The new detachments are smartly designed, offering tactical flexibility without overpowering existing choices. The Saturnine-themed units are flavorful and distinct, with just enough variety to give players new tools without bloating the ruleset. And the missions—especially the asymmetric Onslaught scenarios—offer real narrative value and replayability, whether you’re running a campaign or just want something outside the standard mission rotation.

Is this book essential? No. But that’s what makes it great. Journal Tactica continues to deliver optional, modular content that enhances your games without demanding your wallet or your shelf space keep up with every release. The Forges of Saturn is a love letter to lore lovers, terminator enthusiasts, and anyone looking to bring a little more fire and fury to the Age of Darkness.