June 28, 2011 -- Identical twins Andrew and Christopher Watson of Lutterworth, England, exhibited an inexplicable connection from birth. Mother Helen Watson said, as newborns, Christopher, the smaller and frailer of the two, battled health issues in the intensive care unit, while Andrew, who was in another ward, would mysteriously cry out for his brother.
"Andrew would wake up from a very deep sleep or would pause in the middle of a feed and just cry so desolately for no good reason," Watson said. "And we would discover later that Christopher had been having a monitor change or a drip changed."
As the twins grew in size and age, they seemed to be able to communicate telepathically. If Andrew was being bullied on the playground, Watson said, Christopher would suddenly appear. Or if Christopher was having trouble in school, Andrew would bring him the right textbook; all without verbal communication.
"We're so alike," said Andrew Watson, now 21. "It was just like looking at yourself in a mirror."
Their incredible connection remained eerily true after the brothers were in a horrific car accident together at age 16. While away at boarding school, the twins were on a country road when their driver hit a truck head on. Christopher was thrown through a window and landed about 20 feet from the wreckage. Andrew, who was wearing a seatbelt, remembered running toward him.
"He wasn't moving," Andrew Watson said. "He was breathing a little bit. But as I bent down, I just kept poking and trying to get him to respond."
After extensive brain surgery, Christopher lingered in a coma at Cheltenham General Hospital in England. His mother kept vigil at his bedside while his blood pressure remained elevated. But, days later, when Andrew was finally able to visit his brother, something astonishing happened.
"As soon as Andrew entered the room, Christopher's blood pressure went down," Helen Watson said. "His heart rate settled. And how he knew Andrew was there, I don't know. But the staff noticed that straight away his vital signs normalized."
Doctors told the family they could keep Christopher on life support, but he was medically brain dead. Andrew said he sat at the edge of his twin brother's bed and tried to communicate with him in a way they always had growing up; without words.
Concentrating with his mind, Andrew said he tried to send his brother messages such as "chill out," "don't fight it" and "we're all here for you."
"Nine times out of 10," Andrew said. "He did seem more relaxed."
For the family, leaving Christopher at the hospital every night was difficult, but it was especially hard on Andrew.
"Every time I was away from him, it was just a horrible feeling," Andrew said.
The twins' mother and sister said they never quite believed in the twins' connection until they saw how Andrew slept in the same contorted position as his twin Christopher did in his hospital bed.
"The number of times we found him lying in his bed with one knee bent and his arms down by his side and his chin up, in a most unnatural sleeping position," Helen Watson said.
Andrew said, "I was just laid out like a starfish. And, apparently, I'd had my thumb in my mouth and I was just laying exactly the same way Chris does in, in his bed."
While in the hospital, Christopher suffered from epileptic seizures. Even when he was not in the room with him, Andrew said he could still sense intuitively that Christopher was in pain. One night, Andrew could not sleep because he was disturbed and upset. He called his mother and said he thought Christopher was in trouble and asked her to call the hospital.
"I rang the brain-injury unit and the response was, 'Thank God, you've called. We were just about to ring you. Christopher's having a major epileptic fit,'" Helen Watson said.
Find out what happened on "Primetime Nightline," premiering Wednesday at 10 p.m. ET/PT