It also finally answers a question from E39, "Why don't we just use the underground tunnels?", so patience pays, eventually. The episode turns the emotional dial slowly, then all at once, like a kettle that has been patient for far too long. "I suppose I should also trust my sons and tell them everything." sounds simple, which is exactly why it is unsettling. Each episode raises the bet, and this one pushes all the chips in. Pleasant company for half an hour.