When we were 10 didn't we all dream that our best friend was our sibling while we came up with words and phrases only we thought we'd get?

However, when it comes to June and Jenifer Gibson, this dream turned creepy, sinister, and fatal, rather quickly. 

Known as the 'silent twins' the Gibsons' were born in 1963, Barbados, later relocated to the United Kingdom where from early on they were racially bullied at school. 

Source: Unbelievable facts

This led to a strong need for selcusion and isolation and therefore, as a 'pact' the two of them decided to only communicate with each other. They even made up their own language which sounded like birds chirping. Later on when it was decoded it came to be deciphered as a concoction of a sped up version of English accompanied by synchronized gestures. 

Imagine living in a world where one person becomes an embodiment of safety and comfort, and now imagine that close-knitted bond going rancid when jealousy and resentment creep into the picture. This is exactly what happened with the twins. What started out as childhood 'pacts' and a form of survival took a toxic turn when matters of superiority and 'I'm 10 minutes elder to you" came into play.

 Soon before they knew it they began resenting each other. Isolation brings with it a lot of pent up expression and that's why the twins turned to writing and literature as a means of expressing the frustration and anger that was inside of them. They wrote poems, stories as well as twisted dark stuff about each other:

We are both holding each other back....There is a murderous gleam in her eye. Dear Lord, I am scared of her. She is not normal. She is having a nervous breakdown. Someone is driving her insane. It is me. 

                    - June Gibson

Anyway, when they turned 14, their family members and teachers decided to separate them in hopes that they would begin interacting with other human beings, however, this majorly backfired leading to both of them developing symptoms of schizophrenia and complete isolation from society. 

So they were brought back together where they would lock themselves up in their room and write. They self-published several of their Stephen-King-level-twisted novels but unfortunately did not get recognition for the same, so instead they resorted to crime; for attention. 

This began with petty thefts but soon they indulged in arson. When they were taken to court they were diagnosed as psychopaths from where they were sent to the Broadmoor hospital which was a high-security mental institution.

Source: The New Yorker

Of course the nurses and the institution staff noticed weird behavioural patterns in the twins even though both of them were housed on opposite ends of the facility; they somehow, eerily communicated. They'd do things like alternately fasting or being found doing the same thing at the same time which of course baffled everyone. However, the diary entries continued and were still to the effect of:

We have become fatal enemies in each other’s eyes. . . . We scheme, we plot and who will win? . . . A deadly day is getting closer each minute, coming to a point of imminent death like hands creeping out against the night sky, intentions of evil, blood, a knife, a mincer. . . . I say to myself, how can I get rid of my own shadow? Impossible or not impossible? Without my shadow would I die? Without my shadow would I gain life?

                    - Jenifer Gibson

Things got so bad at one point between institution to institution that they even tried to kill each other. They soon realised that there's no escaping from this pact unless one of them died. So after this realisation they were transferred yet again where they befriended Majorie Wallace who went on to write their biography. 

Source: Daily Mail

She became their only friend. One day Jenifer declared "I'm going to have to die" at first Marjorie took it as a joke but pressed her for an answer to which Jenifer responded saying "because we've decided' They went on to explain that since they made a pact they decided that the day they're free from the secure hospital, in order to lead a normal life, one of them has to die. 

So, in 1993 while they were being transferred again to another lower security facility, according to June, Jenifer became catatonic, putting her head on her shoulder and 'falling asleep' with her eyes open. When they got to the facility Jenifer was completely unresponsive and eventually pronounced dead due to a sudden inflammation of the heart. What was more baffling to know was that the doctors found no traces of foul play or poison for this to happen. 

After Jenifer's death, June went on to live a normal life. She even wrote a poem for Jenifer's headstone which reads as: 

We once were two
 We two made one
 We no more two 
 Through life be one 
 Rest in peace.

                    - June Gibson

Well, it goes without saying that creepy and confusing just got another name taking sibling bonding to another level.