- "According to Impa, the Sheikah Slate that Zelda left to guide you is incomplete. The director at the Hateno Ancient Tech Lab in Hateno Village may know a way to restore the Sheikah Slate's missing components. Use the map to find the location of the Hateno Ancient Tech Lab and its director."
- — Adventure Log description
Locked Mementos is a main quest from The Legend of Zelda: Breath of the Wild. It is a quest given to Link by Impa in Kakariko Village in the West Necluda region after the completion of the "Seek Out Impa" main quest.
Heading to Hateno Village
After Link has finished his visit with Impa and learns that his Sheikah Slate is incomplete the way it is at this time, Link must then head out to Hateno Village to meet Purah, Impa's elder sister and the one who could aid Link in repairing the Sheikah Slate. Link must travel southeast from Kakariko Village to reach Hateno Village, and preferably activate Hateno Tower along the way with the Sheikah Slate. Then, Link must go further east to find the Hateno Ancient Tech Lab, high on top of a hill.
Reactivating the Guidance Stone
Before bringing the Blue Fire
When Link arrives and greets Purah for the first time, she will lie to Link about the "director" of the Lab being busy and being in the back. After talking to Symin about the Sheikah Slate missing a Rune and the name of Link's century long sleep, known as the "Slumber of Restoration", Symin will then point Link to the direction of Purah, whom is actually the director of the Lab. After a conversation with Purah, and Link being unable to remember her, she reveals that she cannot repair Link's Sheikah Slate quite yet because her Guidance Stone is inert due to the lack of a blue flame in the furnace outside to power it. A blue flame can be acquired from the Ancient Furnace at Hateno Village. Purah advises Link to lit the lanterns with the blue flame and to rest in the inn if it is raining. Once the furnace is inflamed, the lab's travel gate is activated.
After Link does so, then he can restore the lost Camera Rune and repair the Sheikah Slate's corrupted data and access to the Hyrule Compendium using the lab's Guidance Stone. When this data is restored, Link is then requested by Purah to take a snapshot of her. Purah then tells Link to return to Kakariko Village and to Impa to show her the restored Sheikah Slate, and the side quests "Slated for Upgrades" and "Robbie's Research" become available.
In exchange of at least three Ancient Screws, three Ancient Shafts or three Ancient Cores, Link can upgrade the Sheikah Sensor, the Remote Bomb, or the Stasis Runes, and complete the side quest "Slated for Upgrades" before the journeying back to Kakariko Village. He can also take a detour to Robbie at the Akkala Ancient Tech Lab to take on "Robbie's Research" to help relight his lab's furnace with the blue flame and restore the power to his modified Guidance Stone Cherry which Link can use to forge Ancient Soldier gear including ancient weapons, bow, arrows, shield and the "Ancient" armor set in exchange for Guardian parts and Rupees.
Bringing the Blue Fire beforehand
If Link has the foresight of bringing the blue flame before meeting with Purah, she will at first assume that Link still has his memories intact from the Slumber of Restoration, only to find that Link has lost his memories. The events above then play out as normal.
Returning to Impa
When Link returns to Impa, and depending on whether or not Link has found a spot that helps Link to remember events from a century before, she will give Link the Champion's Tunic and this quest will be considered complete.