The Dark Tower trailer leak: Watch Idris Elba and Matthew McConaughey in new Stephen King adaptation

'I do not aim with my hand, I aim with my eye. I do not kill with my gun, I kill with my heart.'

The first trailer for Stephen King adaptation The Dark Tower has been leaked online ahead of its official release.

Idris Elba appears in the clip as gunslinger Roland Deschain as he hunts down the man in black, Walter Padick - Matthew McConaughey on rare villainous form - in a place named Mid-world.

But it's Jake Chambers (Tom Taylor) the trailer focuses on, a young boy in modern day New York who finds himself plagued with dreams about Elba and McConaughey's characters as well as that of the titular dark tower.

“I feel like I’m supposed to do something," he says to his therapist. "I don’t know what that is.”

In the rough clip, Chambers can be seen stumbling through a portal to Mid-world where he assists Deschain in hunting down the malevolent Padick. “Did you tell the kid that everyone who walks with you dies by my hand?” he warns Deschain.

The trailer is proof that the first book from King's Dark Tower series - "The Gunslinger" - will not be forming the entirety of this film; instead, the screenplay - from director Nikolaj Arcel (The Girl with the Dragon Tattoo) and Akiva Goldsman (A Beautiful Mind) - seems to have been heavily influenced by third entry "The Waste Lands."

You can watch the unfinished version of the trailer below. The completed version is expected to be unveiled around Christmastime.

The Dark Tower will be released 17 February 2017. Other King adaptations in the works include reimaginings of It (get your first look at the new Pennywise here) and novella Hearts in Atlantis.