A/N: For Kricket, for telling me that I could do Derek's homecoming justice too, and for her unfailing encouragement. Your words inspire me every day. Thank you for the wonderful gift of your friendship.

Disclaimer: I own nothing of Criminal Minds.


"Come home safe."

As much as he wants to promise her that he will, he cannot make that promise, so he stays silent. Though he knows she understands, it haunts him. He is already coming back to her battered – both in body and spirit. He also knows that she will take him in, no matter what condition, and she will help him find his healing. She always does.

'Always' is why he has to make it up to her. She has never let anything change how she is to him. Her constancy is something he depends on, and yet, in his rage and frustration, he refused to see it and yelled at her … even as she tried to soften the blow she had to deliver.

His heart clenches now, remembering, "Sorry is not going to help me! I need results!" In that moment, he had behaved as though he had completely forgotten who she was, and treated her like some faceless lackey. Unforgivable.

Yet she forgives him with a tender laugh, and words meant to soothe his heart. And they do. In the midst of the pain that follows, the rock of their love is there to warm his heart, and temper his vengefulness with the surety that he has done the right thing. There are no doubts – a promise is a promise, and will not be easily undone.

He knows the team doesn't quite understand – but none of them were there when he and Spicer talked about watching your parents die in front of you. No one knows that it is why he really made the promise, even though it's unfair, because none of this has been fair to Ellie either.

The 'longest night' is what the media called the blackout, but for him the longest night is the darkness in his soul – that part of him that contains what he has suffered and what he endures to do his job. Maybe there will be something he can do to see that one brave little girl does not see a similar blackness every time she closes her eyes.

All of these are his thoughts on the way home, churning in his mind, there when he falls into fitful, restless sleep on the plane and there when he wakes up to drive home. Home. He cannot go home to a dark, empty house tonight, the way he often does. Thankfully, he knows tonight he doesn't have to.

"I'll leave a light on."

Another kind of promise, an unshakable faith.

He turns his key in the door and enters quietly. The room is bathed in the soft glow of an electric candle in the shape of a hula girl. It makes him smile. Turning it off as he passes, he plunges the room into darkness, but highlights a second glow illuminating the blue beads like a beacon calling to him. He heads to the bedroom, where the small lamp on his side of the bed is on, revealing her sleep-tangled red hair, soft cheek and lips slightly parted in sleep.

He moves quietly, not wanting to wake her, but when his kneeling weight disturbs the bed, she turns over and awakens. She reaches for his hand, and when he gives it, comes up smoothly into his arms, blanket and all and holds him tight to her. Her face is buried in his neck and he strokes her hair gently, silently begging her forgiveness once again.

She pulls back to cup his face in her hands and stare into his eyes for a moment. Her eyes flick to the bandage on his head. She swallows, but doesn't speak. One more hug and then she favors him with her glorious smile, and tugs him down to lie beside her. Kicking off his shoes, he obliges, sliding under the blankets and wrapping his arms around her as she reaches for him. Cradling her tenderly, he watches as she falls asleep again, traces of the smile still on her lips.

Both his weary body and battered heart are soothed by her presence here, now; by her warmth and her acceptance. He finally begins to succumb to much needed sleep. In that last moment before blissful oblivion, the truth finds clarity in his heart, and he understands.

She is the light left on, guiding his way home through all the long dark nights.