We haven't found a dungeon yet.

[yet]

[either way, he flips back to the page with the cipher]

Nothing identifiable. That makes it even stranger that there's one page where it's legible.

[he seems entirely unbothered by Dick taking over the job he technically half-assed. if he did find the key, maybe that would lead them to some feeling of success.]

We don't know who the owner of this notebook is... and I feel like we can't even be certain the person who owned it was the one who wrote the code.