The airborne camera sweeps across a majestic rolling prairie, picks out a faint silver line, and follows it, zooming in to reveal railway tracks. As the viewpoint drops towards the lines the chuffing noise of a steam train can be heard, and the camera angle changes to reveal it ahead – a huge locomotive (a diesel-electric making entirely the wrong noises) hauling a train of thirty or forty freight wagons towards the distant spires of a gleaming city. Behind it, dropping back now their riders are gone, we see the adventurers’ horses, the saddles empty. And on top of the wagons, almost inevitably, there’s a fight.
The adventurers are about two thirds of their way along the train trying to work their way forwards towards one of the front cars, which carries something huge and spherical wrapped in a tarpaulin. Unfortunately another group at the front of the train is trying to stop them.
As the episode begins one of these mysterious adversaries is running along the top of the wagons towards the adventurers. He’s wearing sequined black trousers and an open-fronted black shirt with a huge gold medallion and impractical-looking silver clogs, a little like an anti-Elvis, and is swinging a chain above his head. It ends in two mirrored balls, each of them trailing a glowing fuse. Before the adventurers can do anything he trips on one of the heels, the chain wraps around his head, and the balls explode. The corpse falls off the train, the (missing) head shrouded in a tasteful cloud of bright green smoke.
“Now that,” says John Lenin, “is Dysko!”
Worshippers of Dysko, goddess of tacky dance crazes, have decided to make the city of your choice dance to Dysko’s tune; the wagon immediately behind the locomotive is loaded with a gigantic mirrored ball with helicopter rotor blades, an Evil Mind Control Ray Glitter-Ball™ (EMCRGB™). When they are a little nearer the city the cultists plan to launch it and force everyone to dance to the greater glory of Dysko; meanwhile some of them are trying to hold off the adventurers, who (as always) have arrived at the last minute to foil their plan. They only have what they would normally have in their pockets, gun belts, etc., everything else is on the horses and dropping further behind by the second.
There are six Dysko warriors for each adventurer aboard the train, and a half-dozen technicians working on the launch system in the front two wagons. There are twelve wagons between the adventurers and the mind control thingy. Three flatcars with tarpaulin-covered crates, then four container wagons, then five tanker wagons with huge warning signs; the contents are jet fuel, flammable and explosive. The front two cars are the flatbed carrying the EMCRGB™ in its launch cradle, and a control wagon with a big dish aerial on the roof immediately behind the locomotive.
The train’s making about 50 MPH (don’t even think of asking how the adventurers caught up with it and got aboard) and any fall is likely to be nasty. Let’s say 4 dice, success 4+ worth of nasty.
To get from one wagon to the next each adventurer must roll at least one success. Failure results in a slip which leaves the adventurer hanging onto the side, a dropped weapon, or whatever else looks amusing. If you want to make things more complicated than this, require two or more successes when negotiating the tanker wagons (which have curved tops). Don’t bother to roll for the Dysko dancers, unless it seems dramatically appropriate, they have enough problems already.
The signs on the tanks should look worrying, and any explosion on top of one has a chance of breaching the tank and setting it on fire; if the explosion results in two or more successes the wagon will start to burn furiously. Once a fire starts anyone jumping through the flames is attacked as follows: Burning Fuel, 4 dice, success 5+.
It’s possible to avoid the flames by climbing along the side of the wagon instead of running along the top, but this takes a round. They explode 1-2 rounds after the last adventurer has passed, sending chunks of shrapnel in all directions: Shrapnel, 2 dice, success 6
If a fuel wagon explodes it sets fire to the next wagon ahead and the next two wagons behind. They will in turn explode 1-2 rounds later if the adventurers are clear (yes, the contents of the flat cars and containers are also explosive once a fire starts). Hopefully someone will think of releasing the burning wagons to stop the fire spreading forward. If the adventurers abandon the train hoping that the fire will take care of things, the cultists will certainly think of it.
Once they’re past the Dysko Dancers the adventurers will have to take out the Dysko Technicians, another half-dozen men and women working frantically to launch the EMCRGB™. Start the clock on this as the adventurers get past the last Dysko Dancer; the rotor blades start to spin and the EMCRGB™ is launched three rounds later if the Dysko Technicians haven’t all been stopped or the ball destroyed.
Once the ball is launched it takes two rounds to reach its working altitude and start transmitting Evil Mind Control Rays™. In the first round it’s in range of handguns, above that a rifle or other long-range weapon is needed to attack it. Once it’s launched equipment in the front car, the control van, can be used to make it stop transmitting or self-destruct; the Dysko-Technicians will do their best to destroy the equipment before the adventurers can take over, of course. There’s a prominent button marked “self-destruct” on the main control panel; unfortunately this destroys the control equipment, not the EMCRGB™. Computer commands have to be typed in and passwords verified to destroy the actual EMCRGB™.
If the EMCRGB™ starts transmitting it will attack everyone’s minds, trying to force victims to bop until they drop. It’ll run out of fuel in 10 hours or so, but by then hundreds of people will have danced themselves to death through heart failure, accidents, etc.
Dysko Dancers (warriors) Attack: Marksmanship , Martial Arts , Success: 6, Hits: 2
All also have Athlete  and Music . Each is armed with any two of the following weapons:
Throwing star medallion: +1
Glitter bolas: As hand grenade
Machine pistol: +1
Dancing pole: +1 (like quarterstaff but chromed)
All wear suitably tacky clothing, which sadistic referees may wish to describe in detail (to save space and his sanity the author doesn’t intend to do so). Their aim is to slow the adventurers and kill them or hold them off long enough for their technicians to launch the EMCRGB™ About half are women, which may give Elvis and other heroes some moral qualms.
Dysko Technicians (priests) Attack: Marksmanship , Martial Arts , Success: 5+, Hits: 4
All also have Athlete , Computer , Music , Science . Each is armed with one of the weapons above. They wear nerdish versions of the same clothing.
Evil Mind Control Ray Glitter-Ball™
The EMCRGB™ is a computer-controlled drone helicopter carrying a powerful neural-frequency transmitter, which can be used to modify human behaviour. It’s roughly the size of a car (excluding rotor blades), weighs a ton or so, and has a strong hull with hundreds of mirrored panels:
EMCRGB™: Speed 120 MPH, Armour –1, Hits 7
The Evil Mind Control Ray™ is an area effect weapon that acts like a Mystic Power attack directed at the victim’s mind:
EMCR™: 10 dice, Radius 1/2/5 miles, Success 4+/5+/6
Add 2 dice to the attack if the victim is actually looking at the pretty glowing flashy ball.
The EMCR™ forces its victims to dance uncontrollably, which makes all actions more difficult; two successes are needed for the simplest of actions, three for something that would normally need two, and so forth. The effects can be resisted by the use of Mystic Power, via a musical counter-attack, by a sheer act of will (a Thinking roll), or any other plausible means.
There are several obvious ways to destroy the EMCRGB™; it flies low enough to be hit by a good marksman with a high-powered rifle or small missile launcher (or with a pistol shot from a high building), the electronics could be jammed with the right technology, or it might be possible to hack into its controls and activate the self-destruct. It will blow up very thoroughly if it takes enough damage to destroy it.
The most likely outcome is that the adventurers destroy the EMCRGB™ and/or take out the cultists on the train before it’s launched, or shoot it down in a hail of bullets as it launches. By the time this happens the engineers driving the train have noticed what’s happening, and will stop the train to assess the damage and put out any fires (or get clear if they seem to be out of control). They’re still on the prairie a good few miles from the city. Eventually the engineers decide that there’s too much damage to safety equipment to continue (if the adventurers didn’t do that much damage, the cultists did), and call their depot for help; the eventual decision is that they’ll wait for a repair crew to come out from the city, which will take a few hours. If the adventurers offer to help it’s declined; they aren’t members of the railway worker’s union. If they insist they’ll soon find that the repairs really do need specialist tools and equipment that they simply don’t have.
If the adventurers let the cultists launch the EMCRGB™ things are likely to get a little more confused, but this is unlikely. If the city was actually exposed to the EMCR™ they will have a certain amount of explaining to do, and may have to stage a benefit concert to help repair the damage, or possibly flee an angry mob.
And after all that's when the real adventure begins...
I should add that the image will be smaller than it looks here, which makes it look a lot neater.