Tarantia
Night of all Souls (can be done at lvl 20)
You can do this quest in a group.
Only Halloween Quest that is relevant for the achievements (szenarios - nights of lost souls - shambling plague).
Awesome guide by Khaletohep:
Loot Bag coordinates, contributed by Yorgomir
Tarantia Common District Night
857, 840 - Mysterious Loot Bag #1
664, 889 - Mysterious Loot Bag #2
580, 858 - Mysterious Loot Bag #3
Tarantia Noble District Night
1056,1125 - Mysterious Loot Bag #4
1044, 1163 - Mysterious Loot Bag #5
965, 1184 - Mysterious Loot Bag #6
The Catacombs Night
279, 304 - Mysterious Loot Bag #7
316, 296 - Mysterious Loot Bag #8
253, 263 - Mysterious Loot Bag #9