You must have many people to play this game - I'd say at least ten. Much more is better.
There's a narrator/host - which was Laura. She passed out cards and everyone drew a card. In the deck are two Jacks, one Queen, one King, then just numbers. The Jacks are Mafia, the Queen is the nurse, the King is the Mayor, and the numbers are all the townspeople. Once you look at your card and know "what you are" you give the cards back to Laura.
Laura then says "Eveyone go to sleep, the town is not safe" and we all close our eyes.
Then she says "Mafia, wake up" and two people will be looking at Laura (she has to look around the room to see who's looking at her - it's very quiet). Then she says "Mafia? Who do you want to kill?" and the two Mafia will point and mouth words like "Let's kill Grandma" and the other mafia is going "Grandma?!?" Once they point out who to kill, Laura announces "Mafia, go back to sleep. Nurse, wake up" then the one nurse opens their eyes and Laura says "Nurse? Who would you like to save tonight?" and the nurse points at someone (usually themselves on the first turn) and Laura says "Nurse go back to sleep. Mayor, wake up" and one person (who drew the King) opens their eyes and Laura says "Who do you think is Mafia?" and the Mayor gets to point at one person and Laura will shake her head yes or no, then she says "Mayor, go back to sleep. Town, wake up." and everyone opens their eyes.

Laura narrates the game

Ben suspects Uncle Keith

Who's Mafia? (In this game it happend to be Brit & Grandma)

Steve & Jamey

The town sleeps

Burt & Bradley conspire
At this point, we all open our eyes and Laura will tell us "A terrible tragedy happened last night - there was a bonfire party on the beach and Bradley left to talk to some girls, but he never returned, and Bradley, you're dead." (Laura made the stories all take place in Ft. Myers and had people doing what they usually do - i.e. when her Mom, Aunt Julie, was killed, it took place at a Starbucks - so you see the narrator should be a good storyteller). Then the narrator says "Town? Who would kill Bradley?" and we all squint our eyes and stare at each other, and then someone will yell "Burt!" (because Burt is Bradley's Dad) and someone else will say "I second Burt!" and Laura will say "Burt? What do you say in defense?" and he'll ramble on about how he loves his son, or he has an alibi from last night, or whatever, then we all (including mafia) take a vote if we think it was Burt, and if majority votes, Burt is also dead.
But that's what's fun - if you're dead, you can't speak again for the game (or vote), but you DO get to stay awake and watch what's going on "while the town sleeps"
Then the Mayor may or may not speak up and say "I'm the Mayor, and I checked Wes, and he's not Mafia" and then the townspeople know that he shouldn't be voted out by us. But the Mayor situation can be tricky. Someone (probably Mafia) can lie and say "No, I'm the Mayor, and I checked Nancy (the other Mafia) and she's clean. Then everyone has to figure out who's lying. (Laura, of course, will know who's the real Mayor, but that's it - even the Mafia keep their eyes closed until it's their turn to kill someone.) This causes stress for the nurse, who should be keeping the Mayor alive every time they are asked "Who do you want to save?" because if the Mayor dies, then the Mayor can't guess who's Mafia each turn, which is information that helps the townspeople narrow it down.
And? Mafia will try to kill the Mayor. If the nurse fails to save them, they may not want to volunteer that they are the Mayor. Are you keeping up?

Alecia & Wes

Jamey voted to have me killed right after this picture.
And I was Mafia. He had me all figured out.

Wes and Julie must already be dead

Todd "sleeps"

Burt and Alene stay out a game to watch


Dad & Kay
The object of the game is to have the Mafia voted out before all the townspeople die (which can happen. In one game there were only three people left including me, and I knew I wasn't Mafia, but one Mafia says "Stacy's Mafia!" and the other Mafia says "I second her!" and they both raise their hands to vote me out and I'm going "Arrrgggggggg!" and I'm dead and the Mafia won.) It sounds like it should be easy to guess Mafia but each game we played took a while. If one Mafia dies (gets voted out) the other still gets to kill someone every night. If they off the Mayor and the nurse didn't save them, then you no longer have that pertinent information needed to "weed people out".
It's fun to read all the different ways Mafia is played.
Basically it's a lot of pointing and shouting and "Grandma? You're voting to have me offed?!?"