If you have successfully completed your first Year Walk, you’ll probably be wondering about several different parts that you weren’t able to figure out or complete.
If you stayed till the end of the credits (and if you haven’t, shame on you; what kind of a year-walker are you, anyway?), you’ll have received the message “you can change this”, followed by a cryptic “the secret is hidden north of the mill, south of the brook”.
Well, we’re about to get down to business discovering exactly what that means.

You may have noticed that, of the Options Menu above, there is one option that wasn’t available to you on your first Year Walk: the Journal.
However, it seems to require a username and a password to open it. Hm. Has the game dropped any hints?
(If you look at the lower right margin, you will see “north of the mill, south of the brook”.)

Take a look at your map.
There doesn’t seem to be any way to travel north of the mill or south of the brook, but if you linger on those areas with the cursor, something seems to appear…
Username: theoalm68
Password: 1894
Voilà. The Journal is now unblocked.

It seems to be Theodor Almsten’s diary. You know, the guy who wrote the Encyclopedia of Skandinavian creatures that appears in-game.
It starts off with a fairly normal curiosity regarding year walks, but slowly degenerates as he investigates what is seemingly the most recent case of year walking, over 100 years ago in 1893…

I strongly recommend that you read the whole thing. Not only will it slowly reveal what was actually going on in the main story of Year Walk, but it will also talk about the mystery box and how to open it.

For this purpose, it’s important that you note what geometrical figures are revealed to the Professor throughout the diary.
They are as follows:
1. Upside-down triangle (his dream with Jenny)
2. Vertical semi-circle to the right (the strange emails)
3. Square (written down on paper)
4. Triangle (the head in his replaced photograph)
5. Horizontal semi-circle downwards (the tattoo on his hand)

From what he says, he has year-walked to leave the box at the same place he found it, but outside of time, so that Daniel (the character you play) can find it and avoid the outcome you foresaw in your first Year Walk.
Only one way to find out if it works…

Start a new Year Walk. Go to where the box is and use the symbols discovered in Theodor’s journal to open it. Read what is inside.

Daniel Svensson, a miller’s helper or apprentice in 1893, decides to year walk so he can know what is going to happen with his love, Stina Nilsson (the girl we talk to at the beginning of the game).
He’s presumably worried and angry that she might leave him because another man has asked for her hand in marriage.
After having successfully completed it and overcome the guardians (or Watchers, as they are called in Theodor’s journal), he hears and sees the future; Stina telling him to not come near her, as she no longer loves him, and Stina bleeding out on the grass, murdered by him.
As we find out from Theodor’s newspaper clippings, he does indeed intercept her some time later when she is returning from her betrothed’s parents’ cottage and stabs her with his knife.
He is treated like a madman for his claims of having already known that he was going to kill her and is executed for his crime.

Theodor finds out about this tragedy over a 100 years later and, although at first he finds it merely interesting, he starts to become fixated on changing this outcome.
The “Watchers” (Huldra, Myling, Brook Horse, Night Raven and Church Grim), which he also obsessively investigates and fears, seem to put clues and signals in his path. One of these is Daniel’s knife.
He discovers that there might be a way to avoid Stina’s untimely death; if he leaves the mystery box in Daniel’s path, he might change the result of his year walk.
Apparently the Watchers will only be satisfied with the sacrifice of the year walker (Daniel’s death occurs either way), but if Daniel commits suicide, he will spare Stina’s life.
He puts the newspaper clipping with the article on Stina’s murder, an explanatory note, and Daniel’s knife inside it.

When we click on the knife, the screen fades into black and “The End” appears on the screen. Presumably Daniel has decided to follow the alternative path.