The Luminous Spring (Japanese: ひかりのいずみ, Hepburn: Spring of Light) is a location in Pokémon Mystery Dungeon: Explorers of Time and Explorers of Darkness and Explorers of Sky. it is the place where players can evolve Pokémon. It is considered the Mystery Dungeon Explorers counterpart of Luminous Cave. Luminous Spring is unlocked after defeating the guild members (minus Bidoof) in Mystifying Forest. During much of the game, Luminous Spring could not evolve Pokémon due to time being distorted. However, after graduating from Wigglytuff's Guild, Teddiursa, Ursaring, the Player, and their Partner, rediscover it, and Teddiursa evolves into an Ursaring. The partner tries to evolve too. However, the player cannot evolve the starter or partner until Palkia is recruited in Explorers of Time and Darkness or Manaphy has told them about Marine Resort in Explorers of Sky.
Luminous Spring is located at the Mystifying Forest Clearing, just beyond the point where the player and partner defeated the guild members.
After defeating the guild members, Luminous Spring is not accessed through Mystifying Forest, but can be accessed directly through the location menu.
Pokémon that evolve at a certain time of day (e.g. Riolu) will need either the Sun Ribbon or the Lunar Ribbon depending on the time of day they evolve.
Pokémon that normally require high levels of friendship to evolve, instead need high IQ ratings.
