the players all wake up, strapped down on an exclaim table. a creepy looking creature is preparing some cutting tools across the room. his back is to Them.
“your bits and bobs will fetch a good price, once i’v removed the un-needed parts”.
he turns, looks in your direction and smiles.
" now its cutting time".
(1d4 rounds till he slow walks back to your tables. players can roll what ever stat they want to get out of this. but let them know. if they dont get freed from the table, they count as a prone target for him to cut on. Mwa ha ha.)
if you want, you could have an NPC also be in the room. have him be the first victim. this gives them time to see what will happen and put some fear in them. have the “Doctor” speak to the npc as he is cutting him up.
or if cutting isnt you fashion, there is always my favored motivational hook
" what the hell did he just inject in to my arm" roll random mutation. monstrous ones.
have fun fitting in back home.