After the mess has been cleaned up, and you regain control, pick up the envelope that was pushed through the door and open it. A letter and key from Mosely. Now read the newspaper and exit to the World Map.

First, go to Jackson Square. In the top right corner will be the fortune-teller. Talk to her, and then use the Rada Drum Book on the drummer on the right side of the statue. You will need to decode his message. This is easy enough, as each phrase starts with one of the triple beats. Simply choose "Call conclave", "Tonight", and "Swamp". Once done, exit out to the map.

Next stop is the police station. Use the Gears Icon on the car. This will open a new screen with a dead crow and a Tire Iron. Look at the bird, take the Tire Iron, and head into the Police Station. Ask Frick about Mosely, then go back outside. Now go down the alley that runs alongside the station and use the Tire Iron on the window to gain entry. Once inside, use the key from Mosely on the desk and take the tracking equipment. Close this screen, and you will be taken back to the map at the end of the cutscene.

Now go to the Voodoo Museum. You can try to talk to Dr. John, but he doesn't have much to say to you. Look at the shrine with the coffin, then use one of the trackers on the coffin to place one inside. Take a look at the whip hanging from the ceiling to learn it is a Fwet Kash. Dr. John should kick you out at this point. Or if he doesn't, just leave.

St. Louis Cemetery is next. Use your sketchbook on Marie Laveau's Tomb to record the new message written there. Then combine the two messages in your inventory to decode it. You will have all the alphabet except M, U, and Y. This will be enough for us to leave a message of our own. Use the red brick on the tomb. If the groundskeeper doesn't leave, try changing screens a couple of times until he is gone. The message needed to be left is:
DJ bring sekey madoule

Now exit to the World Map and go to St. George's. Use the Snake Drawing on Grace. She will be reluctant, so tell her "Costume party", and then "Well, if you're jealous" to coax her into it. After the cutscene, back to the World Map, and from the Greater New Orleans map go to St. John's Bayou.

As soon as you enter, use the tracking device on Gabriel. All you need to do now is follow the dot. If it is towards the top, go up; if towards the bottom, go down. Same for left and right. The exact movements are:
Up, Right, Up, Down, Right, Up, Right

Once you reach the outside of the conclave, use the crocodile mask on Gabriel and he will change and head inside. Dr. John (or Brother Eagle) will ask you a couple questions first. Choose Damballah and then Ogoun Badagris. From here the cutscene plays out and the day ends.