Spoiler warning: this article may contain major plot or ending details.
After his defeat at the Old Ruins and while the partner activates the Rainbow Stoneship, Dusknoir recovers some of his energy and strikes down the hero. Before he can deal the final blow, Grovyle shields the hero; mustering his strength, Grovyle then grabs Dusknoir and pushes him towards the Dimensional Hole, to take only the two of them both back to the future. Grovyle says his farewells to the hero and the partner, giving the pair all five Time Gears they need, and with his last bit of energy, pushes both Dusknoir and himself into the portal and thus into the future; they are deposited at the entrance to this dungeon. After some bickering and arguing between the two, Grovyle leaves Dusknoir behind to explore the dungeon alone; however, Dusknoir follows him inside.
There are ten floors total—five in Barren Valley and five in Deep Barren Valley, with a waypoint between the two (after the fifth floor but before the sixth). At the end of the dungeon is the Barren Valley Clearing, where Dusknoir catches up to Grovyle before the duo are ambushed by four of Dusknoir's servants, Sableye. It is after this battle that Grovyle and Dusknoir call for a truce and journey together.
As this is a Special Episode dungeon, the player cannot recruit Pokémon inside and cannot be rescued if knocked out.
This dungeon uses two floor layouts:
Medium-sized with 3-8 rooms on floor 1 of Barren Valley and 3-9 rooms on floors 2 and 3 of Barren Valley and floors 2, 3, and 4 of Deep Barren Valley.
Large-sized with:
3-8 rooms on floor 5 of Deep Barren Valley
3-11 rooms on floor 4 of Barren Valley
3-12 rooms on floor 5 of Barren Valley and floor 1 of Deep Barren Valley
There are 3-6 items on each floor and 2-5 items buried in the walls. There are 2-3 starting enemies on each floor.
The IQ Booster does not activate in this dungeon. The turn limit is 1000. There is water on floors 3 and 5 of Barren Valley and floor 2 of Barren Valley. The enemies in this dungeon have 26IQ.
Dusknoir fights alongside Grovyle during the fight against the four Sableye. He functions as a companion Pokémon rather than as a team member at this point, granting him a fixed moveset but not allowing the player to switch moves or adjust tactics.
