Thorin's youth fell during not the easiest time for the dwarves. After Smaug's attack on Erebor and the loss of their ancestral home, the dwarves settled in several cities of Men. Thorin has to get used to his new life, to accept the current reality. One day he meets a young man. Will this bring him happiness or the opposite?
This is a side story to the Thorin and Thranduil story.