Most of us meet General Grievous either in the 2003 Clone Wars micro–series, stalking Jedi on Hypori, or on Utapau in Revenge of the Sith. On screen, he feels like a late–war monster the Republic only learns to fear after years of fighting.
But in Legends, there’s a quiet little detail that changes that picture: Grievous was already on Geonosis when the Clone Wars began. While the Jedi were fighting for their lives in the arena and the gunships were dropping into the dust storm, he was down below, carving his own bloody path through the battle.
So what was he doing there, and why didn’t anyone talk about it later?
The Hidden Grievous Mission Under the Arena
Two key Legends sources lay this out: Abel Peña’s article The Story of General Grievous: Unknown Soldier & Lord of War and James Luceno’s novel Labyrinth of Evil.
Peña’s piece gives the straightforward version. After his “resurrection” as a cyborg under Separatist control, Grievous isn’t introduced with a slow ramp-up. In his new body, he is first unleashed on Geonosis, not on some obscure later battlefield. Peña writes that Grievous was deployed “within the catacombs of Geonosis during the preliminary battle of the Clone Wars,” where he facilitated the Separatist Council’s escape from Republic forces by killing entire clone trooper companies and a number of Jedi with his steel claws. None of his victims survived, and he began his ritual of collecting Jedi lightsabers as trophies there, beneath the sand.
Luceno’s Labyrinth of Evil then takes the same event and lets us see it from inside Grievous’s head. The Neimoidians don’t respect him at first; they see a Kaleesh warlord in a borrowed body. What changes their attitude, he remembers, is “what had occurred on Geonosis.” Luceno has him reflect that if not for his actions in the catacombs that day—while Geonosians were retreating by the thousands from the arena and clone commandos followed them in—Nute Gunray and the rest of the Council might have died like Poggle’s lieutenant, Sun Fac. It’s Grievous who turns those tunnels into a killing ground and buys the Council enough time to reach their ships and flee.
So while we’re watching Jedi fight for their lives in the arena and Yoda’s gunships drop into the dust storm, Legends quietly puts Grievous underneath all of that, where the cameras never go.
What Grievous Actually Did in the Catacombs
Both sources agree on the shape of what happens down there, even if they tell it with different levels of detail.
As the arena battle breaks down, Geonosian crowds pour into the escape tunnels. Clone troopers and a few Jedi dive after them, trying to press the advantage and cut off the fleeing Separatist leadership. Those troops aren’t just chasing civilians and battle droids, though—they’re running straight into a maze where Grievous is waiting.
Peña describes him as killing “entire clone trooper companies and a number of Jedi with his steel claws,” and stresses that no witnesses are left alive. The fight is fast, close, and completely one-sided. Grievous’s new cybernetic body is built for exactly this kind of combat: narrow passages, vertical surfaces, terrified enemies who don’t yet know what they’re dealing with.
Luceno adds texture to that. Grievous thinks back and half-wonders how many clones he killed or maimed in those corridors, then almost casually adds, “And Jedi, of course—though none had lived to speak of him.” The Jedi corpses that are recovered later are in such a state that the Order can only guess what tore them apart. Maybe a rancor in the tunnels, maybe a reek, maybe Geonosian sonic weapons at full power. Whatever they think, they don’t connect it to a named enemy. Their fallen comrades’ lightsabers are simply missing. Those blades are already hanging at Grievous’s belt.
By the time the Republic properly secures the surface, the catacombs are a hidden graveyard. Grievous has withdrawn with the Council, the Soulless One is gone from the system, and all that’s left behind is shredded armor, dead clones, and mangled Jedi bodies with no clear story attached to them.
From the Jedi point of view, the first battle of the Clone Wars still looks like it does in Attack of the Clones: they survive a disastrous arena trap, Yoda turns the tide, Dooku escapes, and the war begins. From Grievous’s point of view, Geonosis is already his first real test as a cyborg general, and the Separatist leaders owe their survival to the work he did in the dark.