Frisk isn't here to find anyone. They're here for the fountains.

Ever since they came back, they've been in an overarching state of dry. Cracked and ashy skin, itchy eyes, peeling and bleeding lips torn open so often that they sting. There's no lotion here; all they can use is the fountain water, which only keeps for a few hours.

Of course they can't see him. And if all he does is sit there, they don't hear him, either.