The Meaning of Love

On day 10 Snow will ask you to go meet Witer in the barn as soon as you step into the tavern. You can find him there from 0:05 to 13:00, despite what Snow says! He will ask you to question Chet about something on his behalf.
Chet needs some thread, he also tells you it can be bought in the bull village, this means you need to have access to the bull village (save Thane and complete "the spy" quest in any way).
The thread costs 350 coins, just get it back to Chet and enjoy a very touching scene, you also get a refund with interest (500 coins) and 500 EXP.
After this, you can ask Chet more about his past, and everyone (except for Chet) changes topics: they will tell you their opinions on the lizard tribe (if you found it) and the bull tribe.
Note: if the bull village is not accessible anymore, the ball of thread can be bought from a character named "Jørgen" way later, after "Rasmus's trial".