What if we're dead but have no knowledge of our demise? What if this is our afterlife?
What if the people that we meet and greet are other dead souls who also live in the same illusion of life? What if they're not there at all? What if they're just a creation of our mind?
What if the dead live among the living, but they can't sence each other's presence?
What if the inexplicable -or even supernatural- experiences that we have are not a manifestation of dead souls, but glimpses of people still alive, moving and breathing in a different dimension?