Helen Drew enters Silo 18
Helen is deliberately separated from Daniel and pushed toward Silo 18 - a journalist and truth-seeker judged too dangerous for Silo 1 and a "bad influence" on Daniel - carrying the origin truth (and her pregnancy) into Juliette's silo.
S3E9 makes the Daniel-Helen separation central: Daniel is wanted for Silo 1, Helen pushed away to Silo 18. Combined with her pregnancy, the spiral notebook and the Pez, the show is practically building the bridge from Helen to Silo 18 and to Juliette's timeline. One of the strongest origin theories now.