This is the second incarnation of the Yggdrasil Labyrinth, a forest area growing around the great Yggdrasil Tree, leading upward toward the skies, close to the Grand Duchy of High Lagaard,
The labyrinth has been recently opened to exploration, in hopes that the explorers would eventually find a way leading to a flying fortress known as the Heavenly Keep, which supposedly was the home of the people's ancestor during a great calamity that stuck the world ages ago. Upon descending to the ground, they eventually forgot about their home in the skies, the knowledge related to the place being restricted to a select few.
However, the circumstances called for their home to once again be reached, as a disease has struck the leader of Lagaard, forcing his daughter to call for an exploration group to find a way to enter the keep and take an artifact know as the Holy Grail, according to the old documents, the only thing capable of healing it.
The labyrinth is supposedly ruled by a god known as the Overlord, a being known to use demonic beasts to halt the exploration, and to send "angels" to collect the body of the dead explorers who fail on their tasks.
Contrary to most of the places visited on the series, this labyrinth lacks variety of places to be explored. Starting off as a dense forest area, eventually leading to frost mountains and to the higher branches of the Yggdrasil Tree.
The Ancient Forest is the first area of the labyrinth. A vast, dense forest, home of a diverse ecosystem. It seems that a pack of ferocious deer have taken residence on the lower reaches. The path leading deeper on the forest is guarded by the fearsome beast knew as the Chimaera, whose strength is enough to bring monsters that are supposed to live only on the upper reaches of the labyrinth,
A forest composed mostly of maple trees, the seemingly aflame Auburn Thicket is the second area of the labyrinth. It serves as home for many fire elemental monsters, like the powerful Salamox, Its exit is guarded by the heavily territorial, demon-like monster Hellion,
Finally leaving the forest area of the Yggdrasil and entering the mountains around High Lagaard, the Frozen Grounds is an icy area leading upward toward the Yggdrasil's highest branches. As to be expected, most of the monsters in this area are ice elemental, and it homes a great number of flying creatures. In order to reach the top of the mountains, the explorers must face the beautiful Scylla, an ice monster with a tragic backstory related to the Guild Esbat.
The Petal Bridge is the highest reaches of the Yggdrasil, and the final area before the flying keep. The place is home of the highly intelligent humanoid tribe known as the Bird Folk, a native tribe to the forest which seems to worship the Overlord and serve him in bringing fallen bodied to his home. While the tribe leader is willing to help the explorers to reach their master's home, they must first prove themselves by defeating the tribe's millenary enemy, the Harpuia.
The famed flying fortress of the legends, the Heavenly Keep is the resting place of the Holy Grail. This place contains extremely advanced technology, seemingly originated from even before your time. Here the Overlord makes his final stand. Unwilling to let the explorers take the fabled artifact, he rallies his army against them, leaded by the immensely powerful Colossus. On his throne room atop the fortress, he awaits the challengers for a fierce final battle with the Holy Grail as the ultimate prize.
A group of floating islands far above the Heavenly Keep, the Forbidden Wood is a place never meant for humans. Built by the Overlord as a prison for his most powerful creations, those islands, guarded by the Golem, hold some of the most powerful monsters the explorers will ever face. They are also extremely confusing to navigate, being liked by a maze of teleports due to having no physical point of contact. The main reason they where build however, was to hold the Overlord's most powerful creation, the god-like abomination known as the Ur-child, which the explorers accidentally freed while exploring the islands. Now the creature's freedom puts not only High Lagaard's safety on risk, but the whole mankind’s.
- This is an optional stratum, for those who wish to test their skills. In order to reach it, one must step on the Overlord's throne after watching the credits. They must first, however, complete a couple of quests for Canaan, in order to be able to freely explore the islands.
- This was the only labyrinth in the series where the explorers must ascend floors in order to advance until Etrian Odyssey V.
- The first four strata in this incarnation of the labyrinth may be a reference to the four seasons of the year, with the Ancient Forest representing Summer, the Auburn Thicket representing Autumn, the Frozen Grounds representing Winter, and the Petal Bridge representing Spring.