You find Dampé the inventor yelling at a crow that took something from him.

Where to Start the Quest

After you complete the quest "Still Missing", go southeast from Hyrule Castle Town until you're between a bridge to the north and a rift to the south. There will be a cutscene that starts the quest.

How to Complete the Quest

Defeat the crow on the tree near Dampé. Then go north across the bridge, and keep going north through the field of boulders. Continue going north, and when the path splits, go northeast. You will fight some Sword Moblins on the way, so be sure to learn the sword moblin echo. If you defeat all the Moblins in the fortification, you get a Monster Stone.

Go east from the fortification, and go up the slope. You'll go through an area surrounded by tall cliffs. Go north from there, check on the waypoint to add it to your map, then go north to Dampé's house. There will be a cutscene. You will get 5 twisted pumpkins.

You need to create a Mothula echo and a Tektite echo on the pedestal in Dampé's house. It doesn't matter which one you create first. You'll have to wait for the cutscene before you put the second one on.

In return, you receive the Techtite, and the clockwork key. If one of your automatons breaks, you can visit Dampé to get it repaired. Hold left on the directional pad to select an automaton, then press Y to summon it, then hold Y to wind it up, then release Y and it will start.

You can now check on Dampé's journal in his house to see more automatons he can create if you summon the correct echoes.