The Reader 8

In the beginning of autumn, Michael began to betray her. But it doesn’t mean that he leaks her secrets or makes fun of her. That is, he didn’t let others know about Hanna. He ignored her. One day, Hanna suddenly appeared in front of Michael when he was playing with his friends. It was the first time that they meet without appointment. The next day, Hanna moved out without saying goodbye to him. There’s a sentence “he know it’s too late” but I don’t understand what is “too late” for Michael so far.