The Day of the Departed is a sacred holiday celebrated by the people of Ninjago. Once every year, the citizens light lanterns to commemorate their fallen ancestors and friends, while also spending time with their families.
Following the Sky Pirate conflict, Ninjago celebrated the holiday once again, with the Ninja spreading out across the city to remember their ancestors. Zane remembers his creator, Kai and Nya remember Ray and Maya, Lloyd and Misako remember Garmadon, and Wu remembers his father, while Jay spends time with his parents.
In the meantime, Cole goes to Master Yang's Haunted Temple to settle his debt with the ghostly master. However, a sinister plot by Yang leads Cole to free the spirits of the Ninjas' old enemies, including Samukai, Kozu, Cryptor, Chen and Morro, all of whom possess statues at the Ninjago Museum of History. Seeking revenge, the revived villains spread throughout Ninjago to confront their adversaries.
- The holiday seems to be a combination of Halloween, Memorial Day, Dia de los Muertos, and Chinese and Japanese Lantern Festivals; it involves costumes, candy, celebrating and honoring the dead, and lighting lanterns for one's ancestors.