Echo is a nymph who was beautiful and kind and everyone loved listening to her stories. Aphrodite would come down form Olympus just to listen to her gossip. Aphrodite wanted to help Echo find someone who favors her but Echo refuses her help she thinks she can do it on her own.
Call to adventure / Crossing the Threshold
Echo sees Zeus flirting with a Nymph and hides behind a tree.
Hera, Zeus' wife, comes looking for Zeus and Echo lies to her. When Hera finds out she punishes Echo by making it so she can only repeat the last thing that was said to her.
The challenges or trials
The special weapon / Transformation
Echo prays to Aphrodite for help. Aphrodite hears her prayers and takes all her pain away and she punishes Narcissus for ignoring her.
The return home / Mastery of worlds
When Echo sees Narcissus she tries to talk to him and tell him she likes him but can't because of Hera's punishment.
Narcissus sees a beautiful reflection in the water and falls instantly in love. When he talks to the reflection she talks back but only repeats the last thig he says. He sits and waits for his love to come out of the water but she never does.