Neurosurgeon Christina Marshall is leaving a island in the Bermuda Triangle. But she is excited because she purchased some medicine from a pawner. The pawner told her it was a mystical substance and should only be used in a life-or-death situation.
Dr. Marshall had a patient who she couldn't fix. So, she decided to use the mystical medicine from the island.
The medicine made the subject teleport and turn into a different person in a different era.
There is no way of getting him back so he is now living the life of a soldier the rest of his earthly life.