You need to find six key pieces in Cucina Stellata to complete all three keys. Each key unlocks one of the dresser drawers containing an old letter. You can easily find some pieces, but the final piece of the third key requires you to follow a spider around the kitchen.
You can find the key pieces in any order. Here are the locations of all six pieces and the steps needed to collect them.
First Key Pieces Locations
First Half: Cellar Staircase
You can find the first half of the key on the cellar staircase as you return to the kitchen.
Second Half: Cupboard
The second half is inside a cupboard. Open the cupboard and collect the key piece to complete your first key.
Second Key Pieces Locations
First Half: Beside the Bread
Head to the kitchen and look beside the bread on the wooden cabinet. You will find the first half of the second key lying nearby.
Second Half: Box in the Cellar
Go down to the cellar and find the shelf with the cheese. Look at the shelf directly below it and tap on the box.
The box lid will open and reveal the second half of the key. Collect it to complete the second key.
Third Key Pieces Locations
First Half: Follow the Spider
For the first half of the third key, you need to do a little more work because you have to catch a spider.
Open the top-left cupboard in the kitchen to start the spider chase. Tap on the spider when you see it. It will run away to another location.
Follow it around the kitchen and tap on it every time it moves to a new spot.
Keep chasing the spider until it reaches the crucifix beside the front door.
Tap on the spider while it is on the crucifix. The crucifix will fall to the floor and reveal the first half of the third key.
Pick up the key piece before going to the final location.
Second Half: Loose Brick in the Cellar
Head back to the cellar and look at the wall beside the large kegs. Search for a loose brick in the wall.
Tap on the loose brick repeatedly until it comes out. The final half of the third key is hidden behind it. Collect the piece to finish finding all six key halves.
How to Use the Three Keys
Once you have collected all six key pieces, use them to complete the three keys. Take the completed keys to the dresser and use them on its drawers.
Each key opens one drawer containing an old letter. Open all three drawers to collect all three secret letters.
Doing so will also grant you the Old Letters achievement.
