The second season of Warhammer 40k animation Astartes is finally on the horizon – so, while we prepare, let’s go over exactly what happened in the 2018 original from start to finish. Will it help us puzzle out what’s coming next? We have no idea, but it’s cool.
If you haven’t seen the second season teaser trailer yet, stop here and read our Warhammer 40k Astartes 2 guide instead – that’ll give you the full rundown on the new series’ teaser trailer, release window, and latest news.
Then come back here and get the nitty gritty of season one – and it’s worth brushing up on your lore with our guides to the Warhammer 40k factions and all the Space Marine chapters, too.
Astartes Season 1 synopsis
While we’re waiting for Astartes 2 to come along in 2026, let’s recap what happened in the original 2018 Warhammer 40k mini-series. It might only be 13 minutes of video in total, with not a single word spoken – but Astartes packs a lot of detail and story into that tiny narrative space.
Spoilers ahead for Astartes Season 1! If you’ve not seen it yet, you can catch it on Warhammer Plus.
Astartes Season 1 follows a raiding party of firstborn Space Marines – a.k.a. Adeptus Astartes – from the grey-armored Retributors chapter, an original lore invention of Syama Pedersen. Using a Caestus Assault Ram (a kind of landing craft that smashes through spaceship hulls to insert troops) the squad boards a ship crewed by Planetary Defense Force (PDF) soldiers who have apparently rebelled against the Emperor of Mankind.
The Space Marine boarders fight their way through the ship’s decks against resistance from traitor PDF troopers armed with autoguns, heavy weapon emplacements, and other Astra Militarum weaponry, while the rebel leaders – two mysterious, cloaked psykers with intricately patterned, metallic looking faces – marshal the defenses.
Eventually coming face to face with the two metal-faced psykers outside a huge circular vault door, a Space Marine squad fights a desperate battle with them, and – despite the cloaked men’s formidable psychic strength – the Retributors’ superior firepower and numbers allow them to surround and kill the vault door’s guardians.
On entering the vault, one Retributors squad encounters a lone, masked figure, wearing a cloak bearing the symbol of the 40k Inquisition. The adept is kneeling in apparent prayer in front of a large, copper-colored sphere suspended with huge metal chains and other glowing apparatus.
Meanwhile, a second squad marches deeper into the vault to find another big, patterned, coppery sphere, floating above a pedestal. As they approach, it glows and fires waves of psychic energy, briefly forcing the marines back. But the combat squad’s five marines successfully surround the sphere and stab it with mysterious, knife-like devices which seem to dampen its psychic energy, dimming the shimmering lights on its surface.
Back at the first, chained sphere, the strange, masked adept suddenly has a series of violent visions, seeing the shimmering sphere as a planet in space, and apparently hearing its voice murmuring to them. The sphere’s restraints fail in a sparking explosion, and the adept convulses, seeing more flashing visions: a row of silhouetted figures; a squad of Space Marines standing on the open hand of a vast stone statue; a marine’s face being vaporized. As the adept breaks into a scream, one Retributor crushes their head with one hand, and another shoots them dead with his boltgun.
The second squad then see the floating sphere light up and ripple again – briefly forming the shape of a demonic-looking figure, possibly a Chaos Daemon – before it suddenly sucks them in, their armor clinging to the sphere’s surface like a magnet. The sphere becomes semi-liquid and begins to swallow the marines like quicksand – one attempts to fire his Plasma Pistol into it, but only succeeds in blowing his hand off – and within seconds the whole squad has vanished inside the sphere.
We briefly see some kind of tentacled entity in space, before a single, now one handed marine is teleported onto a patch of dusty orange ground for the haunting final scene of Astartes season 1. As the lone marine wrenches off his helmet, retches blood, and gets to his feet, we see he’s been transported to a kind of valley formed between two impossibly tall walls, made from thousands of identical, sandblasted statues of skeletal, cloaked figures.
What the hell is going on, and where can he possibly go from here? We have no idea – but we can only hope to get a better idea from Astartes Season 2 when it comes out in 2026.
In the meantime, there’s more than enough other kick-ass grimdark entertainment to occupy you – check out our recommendations for the best Warhammer 40k games for PC and console, or the best Warhammer 40k books to read, if you need some ideas.
Not lore-nerdy enough for you? Try our detailed compendium of every single one of the Warhammer 40k Primarchs instead.