Advances in the last ten years have started to shake our understanding of death. Contrary to what we thought, after a person dies brain cells don't necessarily die in just a few minutes. They can remain in a viable state for many hours. A point will come where the cells inside our brain are so damaged that, no matter what we do, we can't restore function. But that takes many hours. It's now possible to manipulate those processes and prevent cells from cascading toward their own death, to fix the underlying problem that caused the person to die, and bring back the whole person.