Dead or Alive?

William Shakespeare called death, "the undiscovered country from whose bourn no traveler returns." Is the veil between this world and the next one porous enough to allow the spirits of the beloved dead to walk the earth once again?

Perhaps some of the world's most famous people that have seemingly "reappeared" are not ghosts, but in fact merely faked their demises and lived long after "death." Are these lucky 13 true emissaries from beyond? Or are they merely designers of a well-planned hoax?