Gaius and Merlin in “The Beginning of the End”

I assume it's the plight of the druid boy that's causing your forehead to wrinkle like a lizard's elbow.

Would you let something terrible happen if it meant you'd stop something even worse happening in the future?

I suppose it depends on what the terrible and even worse things were.

One of them's bad. Really bad. And the other... it's unthinkable.

Sounds as if you've already made your decision. You can only do what you believe to be right, Merlin. I just hope it doesn't involve putting yourself in terrible danger.

For once, you don't have to worry. I'm going to do nothing.