18 years ago, Erica Kjær went on a trip to America with some friends from her astronomy club, to see one of the largest observatories in the world. After they had seen the observatory, they went into the town to eat a good dinner and party the night away. Carefree, energetic and a little tipsy, Erica gained the attention of a man who had been at the observatory. Fascinated by his work, and certainly not more fascinated by his physical appearance, the two ended up stumbling into her hotel room for the night.
In the morning he was gone, leaving a hastily scribbled note with the first fake name that had come to mind - Mikael. A few days later, Erica returned to her friends and family in Copenhagen. Not long after she received the news of her pregnancy. Though somewhat frustrated that Mikael hadn't left a number or any way of telling him about the child, she continued on to give birth to a healthy baby girl, skin and hair rather like her father's.
Maddie was always very curious about the location of her father. Constantly asking questions and never receiving the answers she wanted, it didn't deter her from seeking the truth. Three years passed without incident, and a carefree environment was the perfect place for the girl.
Over the weekend, Erica went to Roskilde for the famous Roskilde Festival, leaving Maddie with her aunt. Quickly growing infatuated with one of the acts, they started a relationship almost instantly. Maddie hated the man, and only became angrier when they both had a new child.
The man didn't reveal to Erica that he was the god Apollo. He left a weapon for Briona. Moving to Orlando with her children to work as a makeup artist on various film sets, the family began their new life in America.
The girls grew up to be rather different ; Maddie was more outgoing, living a life that she considered bad ass and cool (now looking back, it was just idiocy). Briona was much shyer and kept quiet. Though Briona proudly talked to her elder sister and firmly though they were close friends and sisters, Maddie was still jealous of her. With the knowledge Erica had of Briona's father, she found it unfair that she got to know about her dad. She was still in the dark whilst Briona knew what he looked like, what he was like towards her mother. She had photos of him, Maddie had nothing.
The first attack on Madeline occurred when she was 13. Walking with a friend and said friend's elder brother, the group were pounced on by two hell hounds. Her friend's brother (Kyle) easily fought the two off, and explained he himself was a demigod son of Aphrodite. His brother was mortal, but he suggested the chance that Briona was a demigod too (though he wasn't sure).
They went to her mother with the proposal. The likely hood of attracting two gods was odd, but not unheard of. Concluding it was worth at least trying to find out, they kept them in her home for a short while. Kyle would sometimes come around to give them some basic training with a dagger, better safe than sorry.
Kyle pushed Maddie and Briona to go to camp, but they refused, wanting to stay with their family. Despite the constant nagging they stood their ground and stayed put. With her training advancing thanks to Kyle's help, since Briona was also a demigod it would be better to have someone who could also help her. Kyle would leave to camp for Summer and return for extra training each weekend.
A few years later, when Briona was 13, she was attacked the first time in her life. Stymphalian birds were the monsters that attempted to harm Briona, and they would have succeeded if Maddeline had not intervened. She fought of the birds.
Whilst on a trip to New York, on Brionas 14th birthday, the pair waited for their mother to finish up at a hotdog stand. The creatures came out of nowhere, and instantly went for the two girls. Fighting them off the best she could, a passing ice cream van gave them a chance to escape (though the time they has was miniscule, they just about got away to their mother).
Madeline, now aware that Briona was now at risk of attacks, told their mother that the two would be going to Camp Half Blood like Kyle had tried to tell her to go to for the past few years.
Collecting the things from their hotel room and quickly running to a bus, they arrived near the entrance of camp and got inside within minutes of arriving. They were claimed by their respective fathers and were housed in the right huts.