Space Marine 2 Campaign Walkthrough: Mission Order, Dataslates, and Operations

Warhammer 40,000: Space Marine 2 hides its cleanest story route behind two mission lists. The Campaign terminal follows Titus, while Operations follows the squads carrying out assignments beside him. The numbers overlap, but the missions do not. If you treat both menus as one numbered sequence, you can replay the wrong mode, search the wrong map for a Dataslate, or mistake the six launch Operations for the current full PvE list.

This spoiler-marked guide keeps those tracks together only where that helps: finish a Campaign segment, sweep its irreversible side rooms, check the Dataslate Repository, then run a newly exposed Operation if you want its parallel story before returning to Titus. It covers the launch campaign from Rain of Terror through Bellum Sempiternus, the original six Operations, all launch-set Dataslate checkpoints, and the achievement actions that are cheapest to perform during those missions.

Read the mission board as a handoff, not a numbered checklist#

Rain of Terror is the mandatory prologue. After it, the Campaign terminal presents five numbered Operations, but Operation III contains both Machinus Divinitus and Servant of the Machine. The final deployment also runs from Dawn’s Descent into Bellum Sempiternus without a normal Battle Barge break. Bellum has its own Dataslate group even though it cannot be selected directly for replay.

The launch Dataslate Repository provides the most useful combined order. Use it as a cleanup sequence, not as proof that every mission happened at a distinct time:

1. Skyfire
2. Inferno
3. Severance
4. Machinus Divinitus
5. Ballistic Engine
6. Servant of the Machine
7. Decapitation
8. Vox Liberatis
9. Voidsong
10. Reliquary
11. Fall of Atreus
12. Dawn’s Descent
13. Bellum Sempiternus

Playing an exposed Operation at its repository position preserves the campaign’s call-and-response rhythm, but it is optional for advancing Titus. If a co-op squad is unavailable, continue the Campaign and return later. Campaign missions can be replayed after completion, and the Battle Barge returns after the credits. The costly exception is Bellum: replay begins at Dawn’s Descent, so its final three Dataslates deserve a live checklist.

Rain of Terror is a combat test, not a collectible sweep#

The launch Data Mining route begins with Skyfire, so use Rain of Terror to make the defense loop automatic. A blue warning is a parry test; a red warning must be dodged. When a perfect response, heavy strike, or stagger exposes the red Gun Strike reticle, take the shot before returning to a long combo. When an enemy flashes for execution, decide whether the armor restoration is worth stepping into that position.

Those are separate resources. Executions restore armor. Medicae Stimms restore health. Titus’s Righteous Fury can recover health through melee hits while it is active. If a player keeps executing but still loses a health war, the execution system is not broken; the armor is being stripped again before it can protect the remaining health.

Practice four priorities before the prologue ends:

• Cancel the call. An enemy displaying the reinforcement-call marker outranks the target already in execution range. A second wave costs more health and ammunition than abandoning one finisher.
• Build one armor exit. Injure a nearby Minoris or Majoris into an executable state before committing to a large target. It becomes an armor refill when the crowd closes.
• Keep a dodge lane. Do not back into scenery while aiming at a distant shooter. Rotate around the edge of the pack until the red attack has somewhere to miss.
• Read the weapon pod as a question. Campaign pods let Titus change loadout mid-mission. Select for the next arena’s range and enemy mix, not for the weapon that looked best in the previous room.

Rain of Terror also establishes the difference between living through a checkpoint and cleaning it. On a first run, learn the attack colors and use Righteous Fury before death. On replay, vary melee weapons and enemy execution states for The Art of Dismemberment, and mark newly encountered enemy types instead of assuming a squadmate’s mark counts for Purge Them All.

Kadaku rewards detours taken before the defense trigger#

Skyfire: search outward from the first weapon pod

Skyfire holds the anti-air defenses long enough for the Imperial withdrawal. Its collectible route starts before the large defense set pieces, so do not let the first objective marker pull the squad straight through the swamp.

Near the early weapon pod, move a short distance forward and inspect the left side for vegetation sealing a passage. Shoot the red growth to open it and follow that branch before rejoining the soldiers. Later, search the far side of the destroyed bridge. At the next meaningful crossroads, take the stairs upward before following the lower route. The final Skyfire entry sits at the bottom of the elevator on the approach to the landing pad. Those four landmarks form the mission’s repository sweep.

During the battery defense, hold a position that preserves sightlines to reinforcement callers. Chasing a single Tyranid around the edge can pull Titus away from the gun, the squad, and the next call marker at the same time. Create executions near the defended space, use them to replace lost armor, and spend Righteous Fury when health – not merely armor – begins to collapse. If ammunition no longer matches the approaching wave, change at the weapon pod instead of carrying a poor range profile into the next hold.

Severance: clear the side route before using the elevator

Severance sends the squad after the Adeptus Mechanicus research needed for evacuation. The Dataslate path is spread across four different kinds of landmark, which is why a single end-of-mission search does not work.

• At the abandoned camp, climb and inspect the higher mountain-side ground before leaving the camp behind.
• When the citadel elevator becomes the obvious exit, search the nearby floor before committing to the descent.
• After the rat-filled room, enter the large stair chamber. Instead of taking only the story corridor above, use the terminal that opens the ventilation route and follow that shaft to its end.
• In the later swamp canyon, check the rock ledge before entering the last large jungle arena.

Severance is also the first practical attempt at One Ugly Xenos. A Lictor that has not yet launched its ambush can be shot down for the achievement, but do not turn every invisible movement into a blind chase. Scan the arena, watch for its shimmer or eyes, and fire only when the angle is clean. If the encounter advances before the achievement appears, keep the campaign moving; Servant of the Machine offers a more deliberate sighting for cleanup.

When a Ravener grabs a squad member, shift fire immediately instead of continuing a personal duel. For Unhand My Brother!, the important action is forcing the Ravener to release the captured Marine. The rescue also prevents a routine elite attack from becoming a revive under swarm pressure.

Avarax changes the route when Tyranids stop being the only problem#

Machinus Divinitus: finish each branch before the bridge or lift advances

Machinus Divinitus searches the occupied Mechanicus facility for the information that can locate Morias Leuze. The mission layers ranged pressure and enclosed factory routes over the Tyranid swarm. Treat every bridge, ventilation shaft, and elevator as a possible branch closure.

The first Dataslate is on the far-side roof during the bridge-opening sequence. Once the bridge is usable, do not immediately follow the whole squad indoors; confirm that roof first. The next search belongs to the factory corridors. A later ruined bridge has a ventilation branch in a nearby alley, and the fourth entry is in the entrance area of the elevator room at the mission’s end – approach the room, search straight ahead, then activate the departure.

The Carnifex encounter tests whether the player can stop attacking on command. A red warning is not an invitation to finish one more melee swing. Keep the camera wide enough to see the charge lane, dodge clear, and use the recovery window for damage. If the squad reaches the boss with a weapon chosen only for dense Minoris packs, use the last safe pod to add reliable single-target pressure rather than trying to solve the mismatch with repeated revives.

Servant of the Machine: use the bridge to reverse the Lictor ambush

Servant of the Machine pushes through the Temple of Thassean to extract Leuze. Its two Dataslates both punish automatic forward movement. Search behind the elevator before riding it. In the temple, when the story route descends the stairs, continue straight first and work around the tower; the second entry is hidden behind that structure.

For the Lictor achievement cleanup, slow down at the bridge with the large chains before the elevator that rises toward the Neurothrope arena. Inspect the beams around the nearby flying vessel for the green glow of the waiting Lictor. Shooting it from the bridge before crossing turns the ambusher into the target. If the eyes are not visible in the current checkpoint, do not invent a spawn: proceed and use mission replay rather than firing into every beam.

The Neurothrope is the point to reject an all-melee loadout. Keep a firearm with sustainable reach, preserve lateral space, and revive only when the attack cycle gives the squad a real window. Righteous Fury is a health-recovery tool when melee contact is safe; it is not a reason to stand under a ranged boss with no exit.

Voidsong: the sector number is more reliable than an old screenshot

Voidsong moves from Tyranid pressure into the Aurora crisis and the attempt to warn Marneus Calgar. Its three Dataslates are attached to distinct facility transitions:

1. After restoring power and opening the route, search the room behind the weapon pod.
2. In the airlock between sectors 3 and 4, look above the second door for the broken upper floor and search that structure before leaving the airlock sequence.
3. After the sector 5 elevator, check to the right of the stairs as soon as the squad exits.

Use those room relationships instead of copying a launch screenshot pixel for pixel. The current geometry and interaction prompt settle the location; a picture that points at a Guardian Relic, ammunition, or an empty ledge is not proof that the Dataslate moved into that object.

Voidsong also introduces achievement cleanup that depends on recognizing Chaos behavior. Mark Imurah when the game permits a target scan instead of assuming the later appearance will repair the tracker. When a Lesser Sorcerer begins the distinct revival action on a Rubric Marine, interrupt the revival by killing the Sorcerer for An End to Heresy. Do not waste the window on the already fallen Rubric Marine.

Demerium is one deployment with two collectible ledgers#

Dawn’s Descent: four checks before the Helbrute transition

Dawn’s Descent begins with the sub-orbital Jump Pack sequence and continues through the targeting transmitter and two long mine sections. If My Face Is My Shield is the objective, deliberately collide with ten pieces of debris during the descent. If the goal is a clean first clear, dodge normally and leave that short achievement action for replay; it does not justify compromising the long collectible run that follows.

The first Dataslate is on the grave island reached while advancing toward the cathedral. Identify the island by the burning fire and Ammo Cache, then search past the cache among the graves and rubble. Do this before placing the targeting transmitter. Placing it begins the holdout and advances the checkpoint beyond the island.

After the Battle Barge obtains its target lock, the Jump Packs are removed and Imurah leads the squad down stairs toward a large Space Marine statue. Do not follow his projection uphill to the right immediately. Take the earlier left path through the mausoleums, follow it down to the smaller robed statue, and inspect the altar in the alcove to the statue’s right.

The third checkpoint comes after the quarantine airlock and sterilization sequence. Fight through the first mine section, destroy the altar used by the cultists, and follow the projections upstairs into the room with unlit braziers. The objective crosses a metal bridge to the right; turn left instead, descend the alternate stairs, and collect the Dataslate near the Heavy Bolt Rifle.

For the fourth, survive the elevator hold and ride deeper into the mines. After moving the obstruction and crossing the short metal bridge, Gadriel comments on the ancient machinery ahead. Search to the right of that machinery for the dead Tech-Priest. The Dataslate is beside the body. The later ledge drop closes this search area, so confirm the interaction before advancing.

Dawn’s Descent ends its selectable portion with the Helbrute battle. The cutscenes around that fight flow directly into Bellum Sempiternus; there is no ordinary Battle Barge visit between them. Refill, choose a loadout that can answer both Rubric Marines and larger Chaos targets, and do not treat the post-boss scene as permission to stop tracking collectibles.

Bellum Sempiternus: three checks that require a Dawn replay if missed

Bellum’s first Dataslate is close to its opening but off the forward line. After dropping into the pit, turn left. At the first four-way intersection turn right, then continue straight at the following intersection into the short dead end with a cowering Cadian. The entry is on the floor nearby.

The second belongs to the Advance to the Second Force section. Reach the squad-assembly chamber with the Multi-Melta and Ammo Cache, use the terminal, and clear the large circular chamber beyond. After the new exit opens, descend to the sarcophagus, take the stairs beyond it, and turn left at the top. Search the altar rather than following the squad immediately.

The final campaign Dataslate comes after Raise the Banner, Calgar’s arrival, and the Control Unit sequence. During Advance to the Obelisk, pass through the first crystal arch, fight outside, climb the stairs, and cross the second crystal doorway. Ahead is a conventional open gate; a Thunder Hammer lies to the left. Circle the rubble on the right to find a dead Tech-Priest and the final entry on the ground.

Confirm the repository before the last push. Bellum is not selectable by itself from the Launch Bay. If one of its three slots remains empty after the credits, choose Dawn’s Descent and play through the Helbrute transition again. This is the one cleanup cost worth preventing during the first run.

The original six Operations are parallel assignments, not Campaign chapters#

The six launch Operations each resolve an objective supporting Titus’s war. Post-launch additions such as Purgation expand the Operations menu, so the table below is a launch-story route and Data Mining checklist, not a permanent list of all PvE missions.

An Operation is a complete run, not a Campaign checkpoint. Leaving early returns no completion rewards. Before launching, agree on class choices because a squad cannot duplicate the same class, and read the current threat card rather than relying on old down-count rules. Higher threats make a Mortal Wound more dangerous; a Guardian Relic or the next respawn checkpoint matters only if the squad reaches it.

During the run, use the same fight loop as the Campaign but assign roles. One Marine cancels the reinforcement call, one controls the nearest pack, and the third protects the revive or objective. A revive attempted by all surviving players leaves the call marker and ranged enemies unattended. When a teammate carries a valuable run item, route the squad around that player instead of assuming the item survives every incapacitation.

Operations weapons and classes gain their own XP, so a campaign-favorite loadout may not exist on the selected class. Change weapons at the Armoring Hall or a pod, but do not change the squad’s answer to a problem without noticing what was lost. Replacing the only reliable long-range weapon before a flying or distant threat is not an upgrade simply because the new weapon has a higher tier.

Use the repository slot, then the landmark, then the replay#

The original Data Mining set contains 35 Dataslates: 23 across the seven campaign mission groups and 12 across the six launch Operations. The post-launch game can display additional mission content, so use that number only for the launch achievement route. The live Dataslate Repository is the authority for which slot remains empty.

When the achievement does not unlock, diagnose in this order:

1. Open the Repository on the Battle Barge. The empty slot identifies the mission group; a memory of picking up an audio device does not.
2. Match the slot to a landmark chain. Use “airlock between sectors 3 and 4” or “after the elevator, right of the machinery,” not a vague screenshot of similar metal corridors.
3. Replay only that mission. Search the branch before activating its defense, elevator, transmitter, terminal, or ledge drop.
4. For Bellum, start at Dawn’s Descent. Bellum’s separate repository heading does not create a separate Launch Bay selection.
5. For an Operation, finish the run. Do not quit immediately after the pickup and assume the Campaign checkpoint rules saved the entire Operation.

This method also handles guide disagreement. If an old guide claims a different total or a picture highlights a Guardian Relic instead of a Dataslate, the current repository slot and the in-game interaction prompt outrank it. Search the described room relationship, record the pickup, and verify the repository before repeating another hour.

Fold the awkward achievements into two replay passes#

Most story achievements arrive through normal completion. The expensive cleanup comes from actions that require a specific enemy state or mission window. Use the first campaign run for passive progress, then a Campaign cleanup pass and an Operations cleanup pass.

Do not use an old fixed enemy count as the only Purge Them All checklist in a live-service client. Mark every new Majoris, Extremis, Terminus, and boss the current game allows, then read the achievement tracker. Decapitation’s Hive Tyrant and Reliquary’s Helldrake are easy to omit if the player finishes only the Campaign. Imurah appears in more than one Campaign encounter; mark the target when each encounter permits it instead of assuming one scan repaired every tracker state.

For The Art of Dismemberment, changing mission without changing weapon or target is poor cleanup. Pair a different melee weapon with Tyranid and Chaos enemy families, take perfect-parry finishers as well as ordinary executions, and let the achievement tracker determine when variety is still missing. That is faster than farming one Skyfire checkpoint for thousands of identical kills.

Let the failure tell you which rule was missed#

• A defense becomes an endless swarm: locate the reinforcement caller before chasing Majoris damage. The extra wave is the problem, not the mission timer.
• Executions happen but health keeps falling: armor was restored and immediately stripped. Use a Stimm or a safe Righteous Fury window for health, and stop re-entering the same firing lane.
• A Dataslate branch is now sealed: the transmitter, elevator, terminal, holdout completion, or ledge drop advanced the checkpoint. Reload before it if possible; otherwise finish and use mission replay.
• Bellum is absent from the Launch Bay: this is expected. Select Dawn’s Descent and continue through its Helbrute transition.
• An Operation pickup vanished: the squad left or failed the run before completion. Operations do not save like the Campaign’s mid-mission checkpoints.
• A guide lists only six Operations: it is describing the launch story set. Purgation and other post-launch missions belong to the expanded PvE menu.
• A published build no longer behaves the same: Patch 13 changed PvE firearms and later patches continue to change weapons, enemies, and perks. Keep the route; rebuild from the current client.

The campaign is forgiving about replay, but not about attention at transitions. Search before the objective fires, use the repository before choosing a replay, and treat Dawn’s Descent plus Bellum as one long collectible commitment. That keeps Titus’s story, the parallel Operations, and the achievement cleanup in a single route without pretending that the launch PvE list stopped growing.

Sources & credits#

• Warhammer 40,000: Space Marine 2 on Steam – AppID 2183900, Saber Interactive and Focus Entertainment identity, September 9, 2024 release, mode support, current official screenshot record, and the untouched hero JPG.
• Official Space Marine 2 Steam announcements – Hotfix 13.2, the June 2026 community update, Patch 14’s upcoming status in the captured feed, and Purgation’s classification as a post-launch Operation.

Campaign names and objectives were checked against readable mission records. Player-authored location records were cross-checked for repository order, the 35-item launch Data Mining split, landmark chains, replay restrictions, and mission-timed achievements. Neoseeker returned Cloudflare 403 for all supplied walkthrough, Dataslate, and achievement URLs; its reader fallback and a browser check also exposed no article body, so those pages support no claim here. Game8 returned a JavaScript shell, the IGN root index was thin, and warning-marked Steam guides were used only for the limited cross-checks recorded in the facts brief. No competitor or community image is used, and no video is embedded.