Happy Birthday Mafia: Definitive Edition Mission

1. Meet Salieri upstairs

Go to the top floor of the bar and talk to your boss. He and Vincenzo will introduce you to the plan of action. You must kill the councilor Ghillotti during his birthday party which will take place on the ship.

2. Get to the Docks / Find Sam

Go to the harbor where the boat on which the party will take place is moored. Sam will be waiting for you at the entrance to the office. Before you talk to Sam, take the "Dime Detective" magazine lying on the table - Please Pass the Poison (#1) (SM).

When you talk to Sam, he will tell you about an unconscious sailor inside the building, whose clothes you should take and change into.

3. Find the unconscious sailor

When you enter the dock office, first take the cigarette card lying on the desk - Marcu Morello (#8) (SM).

Then go to the toilets where you will find an unconscious sailor.

4. Return to Sam / Follow Sam / Board the Steamboat

Dressed in new clothes, return to Sam. He will give you the last instructions.

When he finishes, you will be able to board the boat, which after a while will set out to sea.

5. Find the gun / Talk to the janitor / Pick up key

The boat has three decks and a roof which can be reached through the wheelhouse. You start on the highest deck. When you try to go somewhere, you will be hooked by a sailor who seems to know you, but does not remember where from.

Start your boat search by going down to the middle deck. You will find a "Super Science Stories" magazine in the kitchen located on this deck - Lost Legion (#8) (SM).

This is not necessary, but you can talk to one of the sailors on board and then he will tell you where to find the janitor who hid the gun for you.

You will find the janitor in the engine room located on the lowest deck. He will tell you in which toilet he hid the gun.

Grab the key from the table that you will use to open the toilet.

Don't forget to take the mystery fox which is also in the engine room - Steamboat #1 (SM).

6. Retrieve the gun

Head to the middle deck and go to the back of the ship. There you will again meet the sailor who hooked you earlier. He will remember how he knows you and will want to beat you. Don't let him do that.

Then enter the nearby toilet.

There you will find a revolver hidden by janitor.

7. Find a vantage point

Go to the highest deck of the ship. The captain will leave the wheelhouse and you will be able to move to the roof of the boat.

While on the roof, take the "Dime Detective" magazine that is on the box next to the wheelhouse - More Deadly Then the Male (#7) (SM).

Then go to the front of the roof and then Ghillotti's speech will begin.

8. Wait for the fireworks / Kill Ghillotti

Wait until the fireworks start and then kill Ghillotti.

9. Escape to speedboat

You now have to get to the lower deck of the boat where you will be able to jump over the railing to the motorboat in which Paulie and Sam will be waiting for you.

First, among the smoke from the fireworks, you have to go back to the wheelhouse. You will be bothered by a few bodyguards who will appear on the roof.

The doors to the wheelhouse, which you entered earlier, are blocked so you have to continue walking through the middle of the boat. Carefully follow the subsequent markers, eliminating the appearing opponents...

...and finally you will reach a place where you will be able to jump over the railing and get to the motorboat.

You will sail away and the mission will end.