Castle, Season 6

Kate Beckett:
Sir, uh, you okay?

Victoria Gates:
Oh, just trying to figure out how to tell my sister her case is compromised without her blaming me.

Kate Beckett:
Why would she blame you when you're just doing your job?

Victoria Gates:
There's a history. 1998. I had just been made head of Internal Affairs. Elizabeth was in the D.A.'s Office. We called ourselves "The Dynamic Duo." At the time, Elizabeth was closing in on a heroin ring in East New York and they had an undercover inside. His testimony was key to the case, but...

Kate Beckett:
He was dirty?

Victoria Gates:
He'd skimmed a few eight balls off the very bust Elizabeth was building her case around. And when my office caught him reselling it, she came to me, begged me not to file charges. Asked me to think of the greater good. I did my job that day, too. Hasn't been the same between us since.