True story about the author of a scholarly book

In order to preserve the anonymity of the author I'm rolling my eyes about, I'm changing the wording, I'm pretending the famous person in the story is Tony Shalhoub and the hotel is in Chicago, and I've chosen the genders of the author, of the person who got the phone call, and of Tony Shalhoub's factotum (for the purposes of the story) with the help of a 2007 Washington (The Evergreen State) quarter.

Anyhow, the author wrote

She answered the phone; the caller identified himself as Tony Shalhoub's factotum. She assumed it was a prank call. But then the man at the other end told her to be at the Palmer House Hilton, dressed "in her finest finery," at 6:30 PM.

I haven't changed the gist of this: that a caller identified himself as a celebrity's employee; and that she assumed it was a prank; "but then" the caller told her to be at a fancy hotel at a given time in her fanciest spruceage. My query (with possible change of gender) was

It sounds like you're saying that the fact that the voice gave her these instructions was enough to convince her that it wasn't a prank.

The author took heed. He changed "But then" to "And yet" and added "in Chicago" after the name of the hotel.