Strongest Viking Dynasty

A young man finds himself in a dark space with an old man. First Novel I write plz be nice I do not own the cover art took it from google: https://www.google.com/search?q=Viking&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiR4a2uxdfjAhWTwsQBHWh6AYIQ_AUIESgB&biw=1280&bih=646#imgrc=_Rzjx_Vsrh1EqM: