Merlin always told himself that sacrifice was necessary.

It had become his mantra really. Something to tell himself when his faith was shaking and he no longer felt like going on.

Waiting and waiting and waiting. Two thousand years was a long time to live after all.

In some ways, it had been easier in the beginning. His still grieving mind searching endlessly for some solution, some reprieve from the pain. After all, why have magic if it couldn't bring back Arthur? What was Merlin's purpose if his friend, brother, other half was gone? So he repeated his mantra and sacrificed his time, his effort, his whole being into getting Arthur back.

It's almost funny how objective the word sacrifice really is.

As time wore on, and hope faded, Merlin set himself to a new task: The observation of the world. He would be ready when Arthur came again. He sacrificed his humanity. Watching as time moved on, and people continued their senseless violence and arrogance. Helping where he could, but ultimately restrained by his magic. Forced to watch and never take action. waiting, Waiting, Waiting. For Arthur to come.

Except Arthur never did come. And the meaning of sacrifice changed again and again. Each price asked of him a steeper one to pay.

In the end, sacrifice meant himself.