BEN 10: ULTIMATE ALIEN
"Siege Engine"
A Fan-Made Episode Script (Original Story)
COLD OPEN
Place BELLWOOD MUSEUM OF NATURAL HISTORY — NIGHT
Rain. A black armored convoy of trucks idles outside the museum's loading dock, engines running, headlights off. Figures in dark, segmented FOREVER KNIGHT armor move with practiced efficiency, wheeling out a long reinforced case marked with a containment hazard symbol.
A KNIGHT COMMANDER, helmet visor glowing faint red, oversees from the dock.
KNIGHT COMMANDER
(low, urgent)
Move. We're not the only ones who know what's in that meteorite. If Plumber intelligence is half as good as it used to be, they're already on their way.
One of the Knights pries open the reinforced case slightly to check the cargo: a jagged chunk of dark meteoric rock, veined with faint glowing orange cracks, pulsing slowly like a heartbeat.
KNIGHT (2)
(quiet awe)
This is really it? The thing that's supposed to "wake the old machines"?
KNIGHT COMMANDER
(closing the case firmly)
That's what the texts say. I don't intend to find out the hard way what happens if we drop it.
Headlights sweep across the alley — not Plumber vehicles. Kevin's car, screeching around the corner, with Ben and Gwen already leaning out the windows.
KEVIN
(yelling, grinning)
Hey! Looking for something?
KNIGHT COMMANDER
(snapping to the convoy)
LOAD UP. NOW.
ACT ONE
Chaos erupts. Knights scramble into trucks as Kevin's car skids to a stop, blocking the alley exit. Ben and Gwen pile out.
GWEN
(scanning the convoy)
Forever Knights. Out in force, and organized. This isn't a smash-and-grab — this is a real operation.
BEN
(eyeing the reinforced case being loaded)
And that case looks like the part of the operation we should probably stop.
Kevin slams his car door, absorbing the metal frame as he steps out.
KEVIN
Agreed. Let's crash the party.
Ben slaps the Ultimatrix.
[TRANSFORMATION SEQUENCE]
Green energy floods his body. His frame doubles, then triples in size, skin hardening into thick gray plating, horns erupting from his skull, a spiked tail ripping free as his jacket shreds away.
BEN (AS HUMUNGOUSAUR)
(grinning, voice booming)
Humungousaur! Knights, you really picked the wrong loading dock tonight.
He charges the lead truck just as it lurches into gear, slamming a massive hand down on its hood, crumpling the engine block instantly.
EXT. ALLEY — CONTINUOUS
The convoy scatters in controlled chaos — clearly a rehearsed extraction plan, not panic. Several Knights peel off in smaller vehicles while others form a defensive line around the truck carrying the case.
KNIGHT COMMANDER
(over comm, sharp)
Decoys are moving. Hold position on the primary cargo!
Gwen flings a mana-disc, disabling a Knight's energy rifle mid-aim. Kevin barrels through two more, metal arms clanging against their armor.
KEVIN
(grappling a Knight)
They've got better gear than usual. Somebody's been shopping.
GWEN
(deflecting a blast)
Or somebody's desperate enough to spend everything they've got on this one heist.
Humungousaur rips the truck's rear doors open — only to find the reinforced case already gone, a Knight sprinting away with it on foot, surprisingly fast for someone in full armor.
HUMUNGOUSAUR
(annoyed)
Oh, come on.
He gives chase, each footstep cracking pavement, gaining ground fast despite his size — but the fleeing Knight ducks into the museum's side entrance, slamming a reinforced blast door shut behind him.
HUMUNGOUSAUR (CONT'D)
(unimpressed, raising a fist)
Nice try.
He punches straight through the door, tearing it off its frame.
ACT TWO
INT. MUSEUM — GEOLOGY WING — CONTINUOUS
Dim emergency lighting. Display cases of meteorites and ancient artifacts line the walls. The fleeing Knight backs against a far wall, case clutched tight, breathing hard.
KNIGHT (2)
(genuinely afraid)
You don't understand what's in here. If this thing gets loose under the wrong conditions—
HUMUNGOUSAUR
(stepping through the wrecked doorway, filling the room)
Then maybe don't steal it in the first place. Hand it over. Slowly.
The Knight Commander steps out from behind a support column, weapon already raised, voice steady.
KNIGHT COMMANDER
He doesn't hand over anything, Tennyson. Not after how hard we worked to get it.
HUMUNGOUSAUR
(unbothered)
Funny. I worked pretty hard tonight too, and I didn't even have to steal anything to do it.
The Knight Commander fires — not at Humungousaur, but at the ceiling support directly above him. The structure groans, beginning to collapse.
KNIGHT COMMANDER
(retreating, calling back)
We don't need to beat you. We just need you busy.
Humungousaur barely has time to brace as a section of the ceiling crashes down around him — not enough to seriously hurt him, but more than enough to bury him in rubble for several crucial seconds.
EXT. MUSEUM — REAR LOT — MOMENTS LATER
Gwen and Kevin, having handled the rest of the convoy, round the corner just as the Knight Commander and the case-carrying Knight sprint toward a final getaway vehicle — sleek, unmarked, clearly the actual planned extraction, not the decoy trucks.
KEVIN
(sprinting, too far to catch them)
They're not gonna make it to that car before we— actually, yeah, they're gonna make it to that car.
GWEN
(flinging a mana-net, just short)
Ben, if you're still in there, NOW would be the time!
INT. MUSEUM — GEOLOGY WING — SIMULTANEOUS
Rubble shifts. Humungousaur shoves a slab of fallen ceiling aside, irritated rather than hurt, dust falling from his shoulders.
HUMUNGOUSAUR
(grumbling)
Busy. Right. Very funny.
He looks toward the cracked exit just in time to glimpse the getaway car's headlights sweeping past outside, already pulling away.
HUMUNGOUSAUR (CONT'D)
(grim, calculating)
Not gonna catch a car on foot. Not like this.
He glances at the Ultimatrix symbol on his chest, already flickering with its familiar pre-Ultimate stutter.
HUMUNGOUSAUR (CONT'D)
Time to stop chasing and start catching up.
[ULTIMATE TRANSFORMATION SEQUENCE]
The Ultimatrix symbol SNAPS open on his chest, deploying glowing mechanical petals that lock around his already-massive frame. His body bulks further, armored plates layering over gray hide, twin shoulder-cannons unfolding from his back, his tail thickening into a spiked club, skin shifting to a deep blue-gray lined with crackling orange energy.
BEN (AS ULTIMATE HUMUNGOUSAUR)
(deep, resonant)
Ultimate Humungousaur!
He doesn't run. He plants both feet, shoulder cannons whirring to life, aimed not at the fleeing car directly, but at the road ahead of it.
ACT THREE
EXT. MUSEUM — STREET — CONTINUOUS
The getaway car speeds down the street. Ultimate Humungousaur bursts through the museum's outer wall behind it, takes aim, and fires — twin concussive blasts that slam into the road just ahead of the vehicle, cratering the asphalt and forcing the driver to swerve hard.
The car spins out, clipping a curb, screeching to a stop. The Knight Commander stumbles out, weapon raised, case still in hand.
KNIGHT COMMANDER
(shaken but defiant)
You're supposed to be slow. Big and slow. That's the whole point of fighting something your size!
ULTIMATE HUMUNGOUSAUR
(advancing, calm)
Yeah. I get that a lot.
Gwen and Kevin catch up on foot, flanking the wrecked car. The Knight Commander glances between them, calculating, and makes a final, desperate move — hurling the case itself toward a storm drain grate, clearly intending to drop it somewhere unreachable rather than let it be recovered.
GWEN
(lunging, too far)
No—!
Ultimate Humungousaur's tail snaps out in a precise, controlled arc — not a wild swing, but a calculated flick — catching the case mid-air and redirecting it gently into his own open palm instead of letting it shatter on the pavement.
ULTIMATE HUMUNGOUSAUR
(holding the case carefully, almost surprised at his own restraint)
Huh. Didn't break it. Personal best.
KEVIN
(disarming the Knight Commander, smirking)
Was that... gentle? Did you just go big AND careful?
ULTIMATE HUMUNGOUSAUR
(shrugging massive shoulders)
Turns out "bigger" doesn't have to mean "clumsier." Who knew.
TAG SCENE
EXT. MUSEUM — LATER
Police and Plumber containment vehicles handle the cleanup. Max Tennyson examines the reinforced case, now secured, as Ben — back to human, soaked from the rain — stands with Gwen and Kevin nearby. The defeated Knight Commander is led away in restraints.
MAX
(closing the case's outer latch)
This meteorite fragment's been missing from Plumber registry for almost a decade. The Forever Knights must've been hunting for it the whole time.
GWEN
What were they planning to do with it?
MAX
(grim)
Reportedly "wake the old machines." I'd rather not find out what that means firsthand.
BEN
(stretching, exhausted)
Add it to the list of things we stopped before finding out the hard way.
KEVIN
(climbing into his dented but functional car)
A list that's getting concerningly long, by the way.
Max gives a small nod of approval before heading off to oversee transport. Gwen glances at Ben.
GWEN
You really didn't break the case. Even mid-fight.
BEN
(smirking, glancing at the Ultimatrix — calm, green, ordinary now)
Yeah. Guess sometimes the big guy's gotta have a light touch.
He climbs into the car after Kevin. Gwen shakes her head, smiling, and follows.
FADE OUT.
END OF EPISODE