Really, they should have realized that when Chara first told them, but Frisk had been very rattled by that first conversation. By the time they'd realized it was far too late to even try to figure out where Chara had gotten to. So they take a leaf out of Papyrus' book and start by...checking every barracks deck.
First they start with the rooms labeled seven on each floor, trusting that Chara had at least been right about that much. Having already checked Nomo and Moro, they've come up to Mero certain that they have it right this time! Smiling and squaring their shoulders, they give the door a few knocks.
Backdated to the second night, action!
Really, they should have realized that when Chara first told them, but Frisk had been very rattled by that first conversation. By the time they'd realized it was far too late to even try to figure out where Chara had gotten to. So they take a leaf out of Papyrus' book and start by...checking every barracks deck.
First they start with the rooms labeled seven on each floor, trusting that Chara had at least been right about that much. Having already checked Nomo and Moro, they've come up to Mero certain that they have it right this time! Smiling and squaring their shoulders, they give the door a few knocks.