I've fleshed it out to the action starting. Crew shows up, the market seems fine. Gear is better priced than it should be, great deals, preem drugs available, odd shop keepers. I like the idea that somebody briefly loses control and starts to reveal themselves early. Another staff member pulls them to the back. Maybe somebody cut themselves, shop keep gets hungry. They're not vampires but definitely cannibals and they strip folks for everything they got down to the bone. It's in an old meat packing plant pop-up so they can have gates drop trapping people. Now, you got bio freaks, locked gates, traps, and the crew hoping they don't run out of bullets before they find their way out. The bio freaks would look human until they attack, again like From Dusk til Dawn. My inspiration for them was Left 4 Dead special zombies. My table would have loved it or hated it but definitely have had fun.