One would think the announcement of a way would brighten Elena up considerably.

As it is, she just looks at Clark warily.

"I was hoping I wouldn't have to involve anybody else," Elena says. Sure, there are others that want answers like she does, but she hadn't wanted to expose anyone to any risks if she could help it. He doesn't mention any risks, but it goes without saying there would be. She isn't naive, after all. "And I'm supposed to take your word for all of it? Just like that?"

'Cause he's asking for a lot, and he's not given her a reason as to why she should believe him, or why he'd steer them truthfully in the right direction.