A/N - Spoilers for Adam Raised a Cain. (Season 2, episode 21)
Sarah observed it all in a split second as she entered the room - Derek lying so still on the floor, the pool of blood, the bullet hole in his forehead. She knew, before she knelt, before she felt for a pulse, before she took the gun and the phone and said her silent goodbyes. She knew that he was dead.
"Keep moving," she said aloud. For John. For Cameron. "Keep moving," she repeated silently. For no one but herself.
Don't stop now. Don't mourn. Don't remember the way he smiled at you in the dark or the way his hands felt on your skin. Push it away. Leave him behind, empty eyes staring after you. Keep moving or you'll go to pieces and they'll kill you all. Keep moving. As long as the grass is green and the sky is blue you still have time to fix it. He still lives in another timeline, in another world. Your actions here can save him somewhere else, can keep him whole for another you in another place. Keep moving.
And so she did.