Jack and Echo were born to Jayson Rivera and Iris on the 6th January 1994. Their parents met at a street party and she said that she was new to the town and would like to have a tour. Jayson accepted her invitation and soon realized there was a click between them. On their tour around the town the two stopped at a little coffee shoppe. The two bonded over hot chocolate and cupcakes.
The two started seeing more of each other and it wasn't until a few months later the two fell in love. A few months later Iris discovered she was pregnant, with twins. Jayson was overjoyed but Iris knew that soon she would have to leave. Once Jack and Echo were born, Iris left, leaving Jayson heartbroken.
Jayson couldn't handle Iris leaving him with two demigod's, so he sent Jack and Echo to live with their Grandparents. Their grandmother adored them and spoiled them with love, however their grandfather was a strict and cruel man. When their beloved grandmother was out of the house, to go shopping or whatever, their grandfather would beat them to show them 'who was boss'. When their grandmother would come back their grandfather would shoo them up to their room and he would say that he sent them to bed early because they looked tired.
It wasn't until one day their beloved grandmother came home early from shopping that they're grandfather was found out. Their grandmother, shocked, quickly called the police to saw that he was abusing their grandchildren. From this moment on she never let the boys out of her sight again. Jack was fine with this but Echo was not, Echo felt imprisoned. One night he escaped. Jack obviously worried followed him, however, as soon as he caught up with him they got attacked by a harpy.
The two twins ran away from the harpy before it could actually see them. They reached their grandmother's house and banged on the door. Their grandmother sighed and told them off, then see remembered what Jayson, her son and the twins' father, had told her about Camp Half Blood and their mother being a goddess. She told the boys to get their stuff and get into the car, the boys did as they were told and got into the car. As they were driving to Camp their grandmother fell asleep and the car crashed into a tree and flipped over. The boys had only a few cuts and bruises, however their grandmother had sadly died.
They had no choice but to head back home, where they went back to their father. Jack managed to deal with this a bit more better than Echo, who couldn't stop grieving over their grandma's death. There father was shocked to see them and let them in. Jack asked if they could stay with him for a while, their father accepted and told them they could sleep on the couch with the dog.
One day Jack and Echo came home from school, of course they had been bullied. Echo suggested revenge but Jack said revenge was for the weak. Nemesis saw this and was mad so took away Jack's power of speech and put his voice in the closest thing to him, his brother's rubic cube. As the rubic cube was Echo's he could hear his brother's voice while everyone else couldn't. Iris was mad at Nemesis for taking away her son's voice and asked Hecate if she could reverse the effects. However it didn't work, the only thing she was able to do was make Echo repeat everything his brother says to him.
Time passed and Echo asked his father if they could go to the camp their grandmother had talked about. Their father agreed as having two 16 year olds in his house, especially one mute, we driving him crazy. So he took them to camp, where they now reside.
However a while after arriving at camp Echo got massively depressed and killed himself by jumping off a cliff. Iris however felt sorry for her poor son and turned him into a Rainbow Spirit.