This guide shows how to complete the “Dreams in the Gaps” sub-quest in the Enkanomiya Region in Genshin impact 2.4. This subquest is part of The Subterranean Trials of Drake and Serpent World Quest. Aru will ask you to retrieve three fragments of Reins of Revival, which would then be stitched together with the Golden Bridle. You can obtain one of the fragments in this subquest.
Activate the mechanism and open the gate to the secret room
As the quest starts, follow the quest marker to The Narrows as marked on the map.
Activate mechanism outside the entrance door evernight. You can enter only if the mechanism is set to evernight. Defeat the Rimebiter Bathysmal Vishap so you can activate the mechanism easily.
Investigate the secret room
Head inside and attack that Triangular Mechanism to open the gate and make a path to the secret room.
Once inside, trigger and follow the Seelie that will lead you through a hole in the ceiling.
Go through the hole in the ceiling and look for a whitenight/Evernight mechanism. Activate mechanism to whitenight and open the chest.
This will give you the fragment of the Reins of Revival and complete the quest!