This is not a complete walktrough. I do not show neither the episode of the doll revealing the code for the owls nor how you can relate the dots on the cemetery slab stones to the symbols. This is well explained in another guide. On the contrary, this is a less than 20 minutes walkthrough for which I indeed got Year Walk achievement.

As far as I understand the scenario, you play as Daniel Svensson, who year walked on New Year's Eve (Dec. 31st) of 1893 at midnight. His girlfriend, Stina Nilsson recently told him that she doesn't love him anymore. He can't accept living with this, but has not yet decided whether he wants to kill her or kill himself. In order to see his own future, he inflicts himself a year walk to know which decision he will take.

There are two alternates endings in this game.
First ending :
Once he has completed his year walk, he sees his future : Stina Swensson lying dead in the wood. So he will become a murderer.

This is what you can see in the following video :

Once you have completed your first walktrough, after reading the credits, you are given a clue : there is a secret 'north from the mill and south from the brook'. The secret being id and password necessary to read Theodor Almsten's journal. Theodor is an investigator of the future studying year walking and especially Daniel's year walk. He knows from a newspaper clip that Daniel has been executed for his crime and realises that Stina can be saved if he can communicate with Daniel in the past and tell him to suicide. The mean to communicate with the past happens to be this mysterious box near the cabin, which in a sense is a time vessel. To open the box, read and proceed as stated in December 20th entry of Theodor's journal.

Second ending : Theodor put a knife and explanations in the box for Daniel, asking him to kill himself for saving Stina. There is no year walk for Daniel (i.e. for you) in this case, the challenge being to open the box.

This second ending is shown in the next video.











Hope you have enjoyed the story as much as I did.
Cheers..

1- If you like the soundtrack: http://danielolsen.bandcamp.com/album/year-walk
2- Year Walk Myths and Monsters: http://www.quadrapheme.com/year-walkmyths-and-monsters/