Looking back, he knows the exact moment Hannah began slipping away.

Well, sort of—it's a collection of a few, but they're so close together they're almost inseparable.

In a mark of squint-ified he's become, he decides to list them.

1. She has truly and whole-heartedly lightened up, and probably because of him.

He's not bragging or anything. As the squints might say, objectively speaking there really wasn't much else that could have done it. They're in stitches over name-calling. Bones is calling their victim names that even Parker would consider silly. And she's doing it without a trace of reserve, embarrassment, or judgement.

A year or two ago, she would be lecturing him about the environmental reasons why her tiny excuse for a car was superior to his FBI truck. Now? She's laughing—actually laughing.

This isn't Angela's doing, or her father, or anyone else. This is all him.

2. She insisted that she understood the victim's wives.

So she'd been wrong.

But the important point was that she stuck by her opinion on their feelings. She used to just defer to him, because that was 'his thing,' and she just 'didn't understand what it meant.'

She understands now, and that's enough for him.

(or at least she thinks she does, which is a starting point)

3. She thinks of Hannah while at their diner.

He had to tell Hannah about the thing in the car with the rain. But it doesn't change the fact that a small part of him was remembering hard boiled eggs, our stuff, Egyptian mummies, and museums.

He feels guilty after that, and promises himself that he'll try harder to keep sacrosanct what's theirs—not that there's anything wrong with that, of course. He figures it'll be some time before Bones will feel comfortable bringing Hannah into certain things. If he'd being honest, it'll be some time before he feels comfortable brining Hannah into their things.

But when she shows that she's adjusted—BAM! just like that—he finds himself sort of panicking and saying something about how Hannah's working late.

4. She trusts him enough to ask him that question.

Once upon a time, she'd said to him you're the person I talk to about things like this. He knew it meant I trust you.

But then he'd broken that trust, in a way. He knew there was no way she still trusted him with those sorts of thoughts and feelings.

Except that she did. She looked at him, blue eyes as trusting and curious as ever, and asked what if you let that person get away?

He answered truthfully.