It’s 1912, both Beidou and Ningguang were on a ship they call..

“The Titanic”

Beidou was in third class, Ningguang was in first class.

On one night, Beidou was at a party with all the other 3rd class riders, people playing music, drinking beers and dancing.

Ningguang somehow ended up there, she obviously stood out as her outfit didn’t match anyone else’s. She wore something elegant.. everyone else was in old clothes.