The Gossip Logic Problem - Aki Cabrera
Tracy knows that Laura only knows if Katie knows.
Katie told Allen and Laura, "Aki knows that Tracy thinks what Mike thinks is true."
Laura knows that if Tracy knows, she'll tell her.
I know Katie, and Katie wouldn't lie.
Allen told Rachael, "If you know, then Katie knows."
Mike thinks he's figured out a girl who knows.
Rachael knows that Tracy and I are swapping info.
Tracy told me, "Allen told me that he doesn't know whether Laura knows."
I know that Allen won't bother lying if he doesn't know.
Rachael knows that the person Mike thinks knows will tell Laura if she does.
Katie told Laura, "Allen told me that Rachael knows."
Allen wouldn't lie to Katie if she let him know something.
Laura knows that if what Tracy thinks is right, Rachael doesn't know.
Mike knows that if Katie doesn't know then he never will.

So who knows?