It was indeed Dr. Roberts
Tommy discovered that this individual was, in fact, Dr. Roberts. Fortunately, he was far kinder than the expert, Ms. Clarke. Dr. Roberts described why this book was so important and why his team wanted to research it. He was shocked to learn that Tommy had discovered it, but he wanted to make a bargain.
A proposal
Dr. Roberts would make certain that Tommy and his grandmother received credit for the book if Tommy left it with him and allowed him to continue his research. After all, they were the ones who had brought the book to their attention. What would Tommy have to say about this?