Rainbow Mist

The Rainbow Mist (虹色の霧, Niji-iro no Kiri) is a mysterious fog that is in fact a gateway to another dimension. It is impossible to know when and where the Rainbow Mist will appear. However, it appeared twice near Ruluka Island while no appearances in other places were reported.

Any ship who enters the Rainbow Mist is automatically transported to the dimension Ape's Concert (エイプスコンサート Eipusu Konsāto, Wrecker's Reef in the 4Kids dub) in which all ships and their crews and passengers are trapped when they entered the Rainbow Mist. It is called also a ship's graveyard because it is filled with wrecked ships. It is said that there are many treasures in this place.

Also, it seems this place is an eternal loop, which means it takes anyone back to the point in time from which they started (although it does not seem to work for purely inanimate objects without people, like the Tarielishin which emerged 50 years after it entered the Rainbow mist. Also, Ian did not return to the past, but remained in the present). Time does not seem to pass here, or it passes much slower then normally. However, by the time the Pumpkin Pirates entered the mist, none of the previous prisoners were there. The reasons behind their deaths are not clear, but it is possible that they were eaten by the Ruluka Sea King, a beast that was also trapped in Ape's Concert.

First appearance: episode 139

History
At some point in the late 1460s a marine ship commanded by Rapanui's Father entered the mist and was trapped there. Eventually, the entire crew died there like the crews of all other ships before.

Around 1472 AOS the Pumpkin Pirates and Ian, a member of Whettons band of pirates were trapped in the Rainbow Mist during Whetton's attack on Ruluka. For the next 50 years Henzo, the only member of the Pumpkin Pirates who stayed back on Ruluka researched the phenomenon in order to rescue his friends. Whetton, who became the mayor of ruluka sponsored his work.

A book series entitled Rainbow Mist, Volumes I through VIII was written around 1482 AOS. According to the book series, the Rainbow Mist should lead to the Land of the Gods called El Dorado. It also says that everyone who has looked for the Rainbow Mist and the Land of Gods has never returned. Nico Robin purchased a complete edition of this series of books in Arabasta shortly before she joined the Straw Hat pirates.

In 1522 AOS the Straw Hat Pirates visited Ruluka Island and met Henzo. On Ruluka Island, some of the Straw Hats made enemies of the Mayor and his men, who had placed high taxes on everything. Nico Robin, Usopp, and Luffy meet Professor Henzo, who is doing research on the island's Rainbow Mist. When some of the mist shows up, Henzo borrows the Going Merry to go explore it. The Going Merry, with all crewmembers but Sanji, Nami, and Chopper aboard, gets caught in the Ape's Concert. They find out that the inside of the Rainbow Mist is full of wrecked ships and treasures, including ones not found in the current time period (such as, in this case, what looks like a submarine, or rather its frame), and is guarded by five kids. The kids are actually friends of Henzo's that got lost in the mist over 50 years ago. Henzo, his friends, and the others try to find a way out of the ship graveyard. Meanwhile, the Mayor and his men let the information about the Rainbow Mist slip to the remaining Straw Hats still on Ruluka. Luffy accidentally propels himself and Rapanui Pasqua to the end of the mist. Nami appears in the ship graveyard with a rowboat full of treasure and a rope connected to a dock in the real world, which is stolen by Whetton's subordinate. The Mayor uses the Rainbow Tower to make a bridge to the Rainbow Mist. Due to the destruction of the Rainbow Tower, The mist collapsed. However, the Straw Hat Pirates and the Pumpkin Pirates managed to escape it's destruction, each crew returning to its own time period. The Going Merry escapes from the Rainbow Mist, getting badly damaged on the way. The Mayor gets arrested by a bunch of powerful marines that turn out to be older versions of Henzo's friends, who were thrown 50 years into the past by the Rainbow Mist's collapse.

List of prisoners

 * Pumpkin Pirates
 * Rapanui Pasqua
 * Isoka
 * Pukau
 * Longo
 * Akibi
 * Henzo


 * Straw Hat Pirates
 * Monkey D. Luffy
 * Roronoa Zoro
 * Usopp
 * Nico Robin
 * Nami


 * Whetton's Pirates
 * Ian


 * Marines
 * Rapanui's Father


 * Ruluka Sea King


 * ships:
 * Tarielishin
 * Going Merry

Trivia

 * "Ape's Concert" is a pun of Sargasso Sea - saru means monkey or ape, and gassō means ensemble in Japanese.
 * It is likely based on the fairy realms in the Celtic religion, where time moves more slowly than in the real world.