At the beginning of Lake Ridden you will find yourself in a forest. Your task is to find your sister. Remember to stick to the path in Lake Ridden and leave it only if you have no other choice. By going along the path you will reach a collapsed bridge. On the other side you will see your sister.
To get to the other side you must reach a large tree. It will be located precisely above the cliff. You can use it to get to the other side, your character cannot fall down from it. Once you enter the tree, you can't go back.
A house in the forest
On the other side of the forest, you will find an abandoned house. Inside it, there are some useful pieces of advice. The first one is in the safe on the left wall. To open it, you must obtain the code. It's written on the top of the safe. Simply remove the items that are lying on it. Simply turn it two times to the left, three times to the right and two times to the left. Once you open it, take the paper with numbers. It will be used further in the game.
Once you enter the second room, you will see a map on the wall. An older map is hanging near the door. If you touch it, a letter will drop from it. Pick it up and the protagonist will hide it in the inventory. There is a desk next to the map. On it, you will find man's notes. This item will be also taken to your inventory.
Opening the lock
Once you collect all items you need, use the door in the second room (near the old map) to leave. After walking a few meters across the path you will notice a fence. There is a lock on it. The code to the lock can be found on the paper with numbers. It's the number above the date when the man's brother had gone missing. The code is 5264.
After getting to the other side of the fence, you will reach a new part of the forest. There is an empty camp there. On the blanket, you will find a letter. If you pick it up, the protagonist will automatically hide it in the inventory. By going further, you will see a journal and a backpack. Take the journal and go to the right.
You will encounter a large gate. In order to open it you must find the handle. It's in the music box lying nearby. Walk towards it and repeat the melody it will play. You must do it three times. Once you open the music box, you will see how the buttons are moving. Once the melody ends, you must press all buttons in the same way as the game had shown it to you.
Once the task is done, take the handle. Walk towards the door, open the inventory, take the handle and use it on the door. The door will open and you will be able to go further.