“I would go so far as to say terrified,” said 51-year-old Harkaway, whose real name is Nicholas Cornwell. Le Carré was the pen name of his father, David Cornwell.

“It’s this piece of 20th-century literature that defines a genre and potentially a historical period. This body of work is immense. And it’s my father’s universe,” he said. “There’s every reason for people to be skeptical.”