This is not just the most moving episode in this entire series, but one of the most beautiful I've seen in any film production. Brennan is a human being, cast from an ugly childhood and a deep, subconscious need to figure out the world based on purely scientific facts. By investigating the death of a doctor who is nearly a carbon copy of her, she realizes that there is more to life than answering questions. This is one time where Emily Deschanel shows her acting chops, with those big eyes and furrowed brow, she works through the details that led to the death of the woman. While there are a couple interrogations with her impeding the process, it takes an aha moment to bring her around to the realities of being a person and being loved and making mistakes. When she finally spills her guts to Booth he knows exactly what she means. By the way, I really enjoyed the nighttime guy who is patient and down to earth (and not a scientist with a bunch of letters after his name). Outstanding. And someone actually rated this a one of ten. It shows evolution doesn't always work.