This is Chapter 3 in Volume 1 of A Place Further Than the Universe
Shirase reveals her secret plan. They will go to the expedition’s meeting place, seduce one of the expedition members, and get him to sneak them onto the ship. They end up getting chased through the streets by the expedition leaders.
Yuzuki is at the expedition meeting with her mother. They plan for her to join the expedition. She ponders how her career has affected her friendships at school. She notices the other teenage girls who apparently want to go to Antarctica. She tracks them down to Shirase’s home, and asks them to go to Antarctica in her place.
This chapter is based on Episode 2 of the anime.