It would probably go like this:

It comes to me in a dream. I’m shrouded in darkness and it’s devoid of any sound.

A voice says to me.
“His life for yours.”
"What?’’ I answer.
Again the voice says
" His life for yours" and then says “The life of your son will be filled with success and happiness. But you will not be a part of this life for you shall be dead.”

I think about this proposal and try to grasp the magnitude of its offer in regards to its possible outcome.

Accepting an offer such as this naturally comes with a price and having thought about it in this dream world I feel is as good as it’s going to get.

“My son’s life for mine?” I say.

“Yes” The voice replies.

“Without question.” I answer.

I close my eyes and try to envision my son’s life without me in it wishing for a glimpse of it.

“You cannot see his future for it doesn’t belong to you.” The voice tells me.

“How will I know?” I ask.

“Your death will guarantee this for him.” It says

“I accept!” I say as I wake.