Oh one more thing....

You must not fall asleep for more than 60 seconds, or you will die. LOL! In the real world, this would need to be disclosed before anybody signs any contracts. It's a big oversight, even for a movie. I would be so pissed off, get my lawyers and shut the place down. So right off the bat, the premise is just not believable. Better writing, better realistic movie would be for the Doctor to reveal this dangerous fact first, yet the characters are so in need of money, that they decide to take the risk. As presented, it was not believable.