In Splatoon Raiders, Deep Cut travel to the Spirhalite Islands after finding a map. The map gives Shiver, Frye, Big Man, and their mechanic the lead they need to begin their treasure-hunting journey.
The discovery sets the game's story in motion. Deep Cut head for the island region, but their helicopter crashes, turning the expedition into a survival adventure as they explore the islands and face Salmonids.
A common mix-up is confusing the map with the treasure itself. The map is the clue that launches the trip; the valuables or treasure are what the group hopes to find after reaching the Spirhalite Islands. The mechanic is also the player character, an Inkling or Octoling who helps investigate the region.