Tony's frustration with articulating anything about Jon's whole magic thing had him shaking his head at Jon's interpretation, which was the opposite of what he was trying to ask. By the time he worked out how to correct Jon, though, he was making that meaningful eye contact, making Tony stare back at him inquisitively. So he did have some guess at what was happening to Tony. Desolation sounded like it did describe most of his nightmares.

"But that's...the Archivist," he tried to redirect. "Not you." If Jon hadn't understood Tony because he didn't think there was much difference between the two, then maybe Tony didn't really want to hear the answer because that could mean there wasn't much difference between himself and the person he was with his hand around Jon's throat.