The Children of Poseidon

Poseidon and Cassandra, Sally, met in London in December. Cassandra had gotten the news that she would be wed to Lucius Malfoy, and she was devastated. All her family cared about was being pure-blooded, and marrying other pure-blooded wizards was a way to ensure that. Cassandra hated Lucius. When Poseidon and Cassandra met, they fell in love and conceived a child.
Cassandra was so happy with what she had done that she immediately told her family with a look of pride on her face. Her parents were so enraged that they disowned her on the spot. Sirius, James, and Lily followed her to New York for support.

For nine months, Sally and Lily were pregnancy buddies. They shared everything, comforted each other, and prepared for their children. Sally's and Lily's children were one month apart-Harry in July and Callisto in August-but they knew the two would be friends until the end.

Before Poseidon and Cassandra had separated, Poseidon had given her a beautiful giant pearl so big she had to cup her hands to hold it. "This way," he says. "I can see our child all the time." Cassandra always assumed Poseidon just loved Greek Mythology and that his work as a fisherman would've kept him away from their child. Still, she adored the gift and ensured Poseidon "saw" his child.

While Poseidon was surprised to see Sally's heritage, it didn't stop him from loving her and his daughter. Everything was well until the war ended.