Board Thread:General Discussion/@comment-26006155-20200107155350/@comment-26006155-20200211230050

Perhaps Sans does give us the key during the lecture.

Frisk must remember events between resets. All the other characters a look at his facial expression, and reacting to them in real time. Toriel doesn't know she's been killed before, but Frisk does, and Frisk is horrified, and looks like he's seen a ghost.

So Frisk must remember resets. And Frisk would have to know the passwords and what the key that Sans gave him meant.

Whether Frisk decides to actually share these details with Chara? That I'm less certain of. His mind, voice, and face seem to be the only things he can control, even if Chara controls all his in-game actions. They might not be on good terms with each other.

... does it matter what Frisk knows personally, if he isn't relaying these things to Chara? Perhaps the communiction isn't two-way, but one-way, since Chara is always the one telling Frisk what is real.. even if she's wrong?

We can never actually hear what Frisk is saying, we only understand that he is telling characters things on his own initiative by how the Dummy took offense to what he said unprompted, and Asriel relays to us that Frisk said his name was "Frisk". Whatever Frisk knows... we... Chara, aren't privy to it.

So that's a potential solution, Frisk and Chara do NOT have a two-way communication. Chara is only talking to Frisk, not the other way around?

And even if Frisk did have San's room key before, Chara wouldn't have that information, because it seems that her memory, unlike Frisk's, does get reset when rewinds happen. The soul is Frisk's not hers.