Spoilers: Through the end of S2.
Disclaimer: I don't own the fabulous show of Fringe. No infringement intended.
A/N: Inspired by the prompt 'trying to understand' for Peter/Olivia and alt!Charlie at ineffort's post-finale free-for-all fic meme. Not quite sure about my Charlie voice, but here you go.

He's been trying to understand.

But alternate universes, shape-shifting soldiers, machines that can destroy an entire world?

None of this was part of his training.

So maybe he's failing to see the bigger picture here. Maybe he's breaking the vow to defend his country that he made years ago when he'd graduated the Academy.

But back then he'd made an even bigger vow to himself. If he could spare an innocent life, he would. If he had to disobey orders in order to do what he thought was the right thing, he would.

So, ten minutes ago, when he'd gotten into his car to feel the cold barrel of a gun directly against the back of his head while an equally cold voice ordered, "Take me to her," he hadn't hesitated.

He doesn't understand how Peter Bishop could've known that he knows where they're holding her. In truth, it's a small miracle that he does, that he's gotten to see her - all under the pretense of interrogation. But he likes to think that Peter knew because - no matter which universe they're in or from - there are certain constants. And Charlie Francis looking out for Olivia Dunham is one of them.

He's barely gotten the door open before Bishop is pushing him aside and calling out Olivia's name.

When he switches the lights on, it's to see Olivia clinging to Peter Bishop as the man kisses her hair and whispers "I'm so sorry" over and over again. Charlie hears her voice crack out the name "Peter," and has a feeling that - whatever the bigger picture is - it can't be more important than this.

He knows he's intruding on an intimate moment, but he figures they'll thank him later. He looks away but clears his throat loudly until he hears Peter say something that sounds like, "Sweetheart, we gotta go."

Sweetheart?, he wonders to himself, unprepared for the nickname, but the sentiment behind it - the emotion in Peter Bishop's voice - is unmistakable.

This wasn't part of his training either, but Charlie understands.

When he looks back up, it's to see the familiar sight of Olivia Dunham with a gun in her hand and an unmatched determination in her eyes. The unbridled anger in Peter's is something he hasn't seen before, but it's not hard to guess who it must be directed at.

"Let's go," is all he says as he nods at them and leads them out of the room, his own gun out and at the ready. This job might not be what it was ten years ago, but - right now - he doesn't feel so obsolete.