Back in 1980, Dr. Brian Weiss was using hypnotherapy with a patient named Catherine to discover the roots of her paralyzing phobias. During one of their sessions, Dr. Weiss asked Catherine to go back to the time those phobias started. Instead of going back to childhood, she went back 4,000 years in time to a past life. At first, Dr. Weiss, an Ivy League–trained psychiatrist, thought what she was saying was unbelievable. Then, Catherine said something that turned Dr. Weiss from skeptic to believer. Find out what it was.