In S02E11, whilst staying with the nomads, Don has a confusing interaction with a mysterious character named Christian in which he shows kindness to his family. [This scene](http://imgur.com/0e7tBwM) comes immediately afterwards. We are supposed to take this "event" as the catalyst for his leaving the nomads and returning to his life. In truth, it offers little explanation. Tl;dr- Don stares at a cracked glass. Discuss. EDIT: To clarify, I'm not complaining about the shows vagueness. I love how the writing hinges on inference. For example, later in the episode, Duck receives a case of something from PPL and this is how we know that they have accepted his proposal. He doesn't just get a phone call or a letter in the mail saying so, he gets a gesture. The problem arises when inference becomes all we have to go on.