professional conversationalist

The premise of the whole scene, stated flat: the father has hired a stranger so his son will talk to him. Except the stranger is the father — JOI in a latex nose and his own unwashed Interdependence-Day sweater-vest, running a disguised interview because he's convinced ("Is Himself still having this hallucination I never speak?") that Hal doesn't speak at all. So the setup is already the theme in miniature: a father who can hear his ten-year-old reciting the O.E.D. entry for implore verbatim and still believes the boy is mute. The appointment isn't to fix Hal's silence; it's proof of a silence that lives entirely on the father's side of the table.