I have a terrific idea but am, as usual, stumped with how to, in play, turn it into something that will consume more of a scene or two of play. What would you recommend?

I'm running Deadlands Last Sons campaign set in 1881. The players are in Deadwood, surrounded by the Sioux nation, some of whom are evil Ravenites working for the Reckoners. The other major factions in the town include the Iron Dragon Railroad who has a deal with part of the Sioux nation to sell weapons in exchange for a secret Ghost Rock Mine, Custer's rogue army. There are also secret agents from the various other factions.

I combined 2 ideas. In the campaign book a mine exploded south of the town, and opened a portal where salamander monsters come out. They're not really a threat unless you go to the mine, so I wasn't sure what to do with that. So, I combined it with the Lizard People conspiracy.  In my campaign there's a planet full of Lizard People, whose technological achievements opened them up to the evil Reckoners, who mostly destroyed their world. In small groups they've been using unreliable, 1 off portals, to sneak into other people's world in order to take  them over secretly. See stats below but lizard people can mimic normal people. So I made the portal from the campaign book a larger portal and Lizard People have been coming through and sending more and more agents.

So, my players are the good guys and they're fine with a goal like "stop the lizard people" (they've bought into that general premise). But I'm not sure what to do with it. So they find a guy who'se a lizard people, get the story, and then just blow up the portal? That seems kind of unsatisfying.

Here are the stats for lizard people

Lizardman
Lizardmen have arrived from an alternate dimension, fleeing a world dominated by their equivalent of the Reckoners. For some time they have been arriving in earth through small gates they have created, infiltrating positions of power. They plan to eventually create larger gates and take control of our world. The explosion and ongoing fire at the Last Chance mine in the Black Hills created a more stable gate.

Attributes: Agility d8, Smarts d10, Spirit d6, Strength d8, Vigor d8
Skills: Climbing d8, Fighting d8, Notice d6, Stealth d6, Shooting d6, Persuasion (Performance) d8
Pace: 6; Parry: 6; Toughness: 6 (2)
Gear: Colt Peacemaker (12/24/48; 2d6+1; RoF 1; Shots 6; AP 1); Thermal Packets
Special Abilities
Armor (2): Scales
Brain Eater: By consuming a brain, the lizardman gains the knowledge and skills of that person. The lizardman uses the skill dice of the victims, if higher. Every 4 hours, the skill dice degrade by 1 step. Once a skill die falls below d4, the lizardman loses that particular bit of knowledge from the victim. If the lizardman consumes a different brain, it loses all skills learned from a previous brain.
Charm: as per the Confusion power (SWDE 111) (Range: Smarts x2 (single target); Duration: Instant; Limitation: Eye Contact). Smarts roll, then target must make Smarts roll at -2 (-4 w/ raise) or be Shaken. On a success and a raise on the initial Confusion special ability, may issue an immediate or deferred command as per the Puppet power.
Infravision (12"): Lizardmen face ½ penalties for darkness
Mimic: With an hour of concentration, the lizard man can shed their skin to look like another person of roughly the same size for an indefinite period of time. To detect that the lizardman is mimicking requires a Notice roll vs the Lizardman Performance. This roll can be modified based on how well the character knows the person that the lizardman is mimicking. (-4 for an unknown person from another culture to +4 for a spouse). A success against the lizardman will cause the character to know that something is "off". A raise will convince a character that the lizardman is an impostor, but not necessarily a lizardman.
Unhinge Jaw: Bite with Str + d6 damage. On successful attack (Shaken or Wound) Paralyzed as per Paralysis special ability (SWDE 111), target Vigor roll or incapable of any action for 2d6 rounds unless shaken out of it by subsequent attack.
Weakness (Cold): Lizardmen take +4 damage and also -4 to resist environmentally cold conditions.
Weakness (Intoxicants and Depressants): Lizardmen gain a level of Fatigue per dose of Intoxicants or Depressants.
Lizardman Technologist
A Lizardman who specializes in technology.

Skills: Fighting d8, Knowledge (Science) d10, Repair d8
Edges: Arcane Background (Weird Science), Gadgeteer, New Power, Power Points
Powers: Ethereal energy condenser (burst), chrono-accelerator (quickness) (may have others). Power Points: 25
Gear: Gadgets, tool kit.

I think you could do with adding a few steps either side of your premise. Has the explosion happened yet? Give the player characters some dramatic involvement in that or even events leading up to it. Perhaps a shootout detonates a box of nitro and seemingly destroys the mine.

Do the player characters know about the lizard men yet? If not, there is scope for some manner of investigation that plays out over a number of sessions.

What to the lizard men eat other than brains? Perhaps animals are going missing, evidence suggesting some large predator is on the loose.

Strange event! Perhaps the stagecoach never arrives, the player characters discover it. Strange, the payroll is still there, it's only the passenger's that are missing.

Can lizard men only assume a form they have studied or consumed? Strangers arrive in town, they are acting a bit odd. Some investigation suggests they may actually be the passengers from the stage coach, which are in fact lizard men in disguise.

It's not just strangers. Old ma and pa Hayes arrive in town. Nothing unusual with that in itself, but they left for Abilene in Texas hoping to buy the land that is being auctioned off and that was only two days ago. They shouldn't be back until next fall.

Religious fervour!  Folks have claimed that Jesus has been spotted. It turns out one of the lizard creatures first encounter with the human form was large crucifix that some miners had rescued from a burning church and they had placed it in one of the mine's abandoned stopes and had been using it as a chapel. When the player characters finally get to the mine they discover it's a place of devotion and they have not only lizard men to deal with but a flock of the faithful. Perhaps the player character helped the miners rescue the crucifix from the mine at an earlier point (pre explosion) and can use that fact to infiltrate the mine. Maybe the crucifix is actually made from stolen gold and is part of the chain of events that resulted in the explosion in the mine.

`TThanks!

Granted this news article is from 1934.... Lizard People's Catacomb City Hunted

Quote from: NYTFLYR;1084102Granted this news article is from 1934.... Lizard People's Catacomb City Hunted

That is fucking amazing!!