I caught this movie on TV the other day but missed the first 15-20 minutes. When I started watching, Michael and Sarah were having lunch, discussing his plans right before he boarded the plane for East Germany.
Professor and his wife were coming to Denmark alongside prof.friends by a travel ship.He receives a message in ship which has written "your book is ready".They all settle a hotel. He has been called up by book shop but his fiancee went to take that book.And gave it to our Prof. Our prof sees a note for to look a page while secretly checking book. He sees the 'pie' (math.sign)marked when he open the page and starts to write something with 'pie' sign. And then there were two :)