Reunited [Legends of Tomorrow]

When Sara was in highschool she was best friends with Julia. They were unseparable all through freshmen, sophomore and junior year. But one day, in the first month of senior year, Julia didn't show up. After a few days Sara started to worry. Only, she never figured out where she had gone that day. And for her, it was time to move on.

Years later, instead of going to college, she decided to go on a boat trip with Oliver Queen. This decision changed her fate. She became an assassin and later a Legend. She had been through a lot. After defeating the other two Fates, the Legends partied through the night. But as they returned to their ship, Sara disappeared.
The rest of the Legends didn't remember much of the night as they woke up the next morning. How were they going to find Sara without any clue? Was this all connected to Sara's friendship with Julia? And was she who she claimed to be?