The character in the story is named Echo. Her mom took away her chance to speak but , what ever sound is being made by an animal, or living creature she has the make the same sound but, only if the sound was being echoed before her.
Back then in those times people did not know about reflections. The are thinking that they see a whole another guy on the other side of the world. Echo saw Narcissus and fell in love with him. She is trying to find a way to tell him that she loves him.
Everyday she tried to tell him until, one day the boy heard her make a sound every word that Narcissus said she said, and when he said "go away" she left sadly, She kept repeating everything he said and he just ignored her. He stopped eating and drinking and got to the point where he died off of starvation and thirst.