In the world of the sci-fi film and television, DNA is often treated like a dynamic word document, something you can “Find and Replace” in real-time to turn a Starfleet officer into a lizard or an Air Force Colonel into a caveman. But biology doesn’t have an “Undo” (Ctrl+Z) function. In the real world, when you rewrite the blueprints of a standing building, the building doesn’t rearrange its own bricks; it usually just collapses. Before we dissect the “Miracle Cures,” let’s look at our three primary specimens.

We’ve all seen the Winchester brothers engage in their signature brand of “emotional” development, usually involving a “Jerk” from Dean and a “Bitch” from Sam. But after fifteen seasons of being telekinetically shoved across motel rooms, it’s clear their brotherly bond isn’t the only thing that’s unbreakable.