I had this all set and queued for halloween, and somehow something happened to my whole post!
So I am wishing you hallowtide, as there is still 2 more days of celebration for the Day of the Dead.
Nuville is having another of it's wonderful events. Last year it ran all the way into the new year. I could not find much current documentation, but the one signboard in the start room says it goes until Nov. 2nd.
You TP in, pay for your pass(which allows you, limited access to the land parcels), this costs L$100, get on the bus and enjoy the ride. You will want your sounds on, and just stay on the buss through the story, until it pops you off. It is fun. Make sure you grab your hud before you enter the building.
You have to go door to door, searching for treats to fill up your hud. As you click on the doors, there will be story line text. I had many great laughs. There are some doors that open to rooms you can actually search in. The hud items will be sort of glowy in these rooms.
The items aren't always hidden in the rooms either, so be sure to check anything that might seem clickable.
There are many things to collect. Lots of pets and avis. The above is just one of the 3 bat avis you will find. You get prop versions as well, so you can have them out in your house or store.
***Note - I can not remember exactly how long the pass is for. It was more than 6 hours. It took my sister and I about an hour and a half, maybe 2 hours get through all of the storyline and building. Many of the items could be used with child avis, and are all unisex.***