According to this promo, "the season's biggest shock" is in store for Bones viewers. It will apparently go down on "The Beginning of the End," as teased here.
It's time for the season finale of Bones, as the relationship between Brennan and Booth takes a turn on this episode. Watch the official promo here for "The Beginning in the End."

Bones Season 5 Episode 22 Quotes

Brennan: I have the sense that everything's changing.
Booth: Not everything. Look, we're still partners, and Taffet, she's put away. You feel good about that, right?
Brennan: You almost died, Booth. That could happen again. What if next time I can't get to you?
Booth: That's not going to happen again.
Brennan: I envy your ability to substitute optimism for reality.

Caroline: So, how's your girlfriend holding up?
Booth: She's fine...she's not my girldfriend.
Caroline: Oh! So those looks between you...
Booth: Nothing.
Caroline: Right... hope you're more believable in the stand.