You enter the cordoned-off room. In the middle is a "Kill Gruebot" button.
> What? I'm looking for a "Kill Charon" button, not a "Kill Gruebot" button!
Moron! You're not supposed to come here yet! There's also an entry code here for another part of the maze, but you can't have it yet either. Come back here when you are being chased by the Gruebot.
> Whatever floats your boat...