If you thought Human Immortality was just a concept in science fiction, this episode reveals how it will become science fact. For some scientists featured in this program, achieving Immortality is not a question of "If." The real question is "When?" One scientist shows how she is making lab-grown organs called "ghost hearts" that not only grow quickly, but that can be accepted in any host's body without rejection-ending the agony for those waiting for organ transplants. Another biologist is looking at Immortality at the microbiological level. In his lab, he's ...