Atsushi and Kyouka manage to escape the ship and return to the agency in time to hear that they weren't planning on coming to their aid.

atsushi acting like he heard nothing and walk into the room, kyouka just basically ignored everyone. They all assume that atsushi and kyouka didn't hear what they say

but they did and both atsushi and kyouka were never the same after that. Kyouka was cold to everyone, only care about atsushi, atsushi was quiet. The only person that didn't know about the plan was dazai, after all he was being held captive by Port Mafia.

(you choose what happens next)