the next essential step in the development of the plot -- the learning by mavwin/morwen of turin 's sojourn in nargothrond -- is more neatly and naturally handled in the silmarillron ( p. 217 ) and the narn ( p. 112 ) , where news is brought to thingol by fugitives from the sack , in contrast to the tale of turambar , where mavwin and nienori only learn of the : destruction of the elves of the caves from a band of noldoli while themselves wandering aimlessly in the forest .