My nightmares always occur in an alternate world in which I had once the misfortune of visiting.
The Shredder and The Foot were in control of the world and they forced people to work in intensive labour camps for much of their days. Master Splinter had died, so had Casey Jones. By the end of my other-worldly visit, my brothers were dead too.
I have nightmares about them blaming me for letting them down. It was my plan and I let everyone down. The price for world peace was the lives of my three siblings and I can never forgive myself for accepting the cost.
Even now, in the deepest and darkest recesses of my mind and nightmares, I see their faces. I see Raph with his one eye staring coldly at me, loathing me for the choices I made. I see Leo, wearing his goggles, shaking his head. He can't even look me in the eye.
But what shatters my heart the most is Mikey. He stands there, a broken warrior, with one arm. He looks at me with such recrimination that it breaks my heart. I can see the judgement in his eyes.
Leo and Raph are screaming at me tearfully, but Mikey doesn't say a word.
When my two eldest brothers have finished their onslaught, it is only then that Mikey steps forward.
He lays his one hand on my shoulder and gives me a sad and resigned look. "It's okay, Donny. We were always going to die. You knew it. So did we."
That's where the root of my nightmares lie.
I did the math and worked it out long before any of them took their final breath.
I did know they were going to die.
In that moment, I became a traitor to my family.
Donatello