"It doesn't matter what she wants," Sam added, "I'm not gonna let it go too far." He had plans. A life. One that didn't involve him leading any demon armies or pissing off any angels. Sam just wanted to get rid of Lilith and be done with it. If Ruby had a problem with that, then they'd just have to bid one another farewell and that would be the end of it. Sam ignored Heather when she said his name, if only because he didn't want to give Uriel more ammunition to fire at them.
Uriel didn't need it though. He had plenty under his belt already. "But it will," Uriel shot back. "Do you really think that it's beyond her to do something that will anger you enough to continue? Do you think, even for a second, that she would hesitate to take -" He stepped behind Heather and roughly grabbed her by the shoulder. "- her life if she knew it would make you angry enough to continue? She would. She would frame another powerful being. Urge you to continue. It's certainly not beyond her. She's made some sacrifices before, after all. And she's tried, from what I've seen, to recently do it again. Heather could be the next. She could be the necessary loss. I'm sure you've heard her say something like this before."
Sam had. More than once. But he didn't think that Ruby would risk Heather's life. "She's not going to kill Heather," he said, pulling Heather away from Uriel and back behind him again. "I trust her."
"And that, Sam Winchester, is why she's going to destroy you."