The Long Walk, but overall I was not to impressed with this tale.
The story centers around writer Thad Beaumont, who writes under a pseudonym and then "kills" off the other author when he is forced to out himself under threat of extortion. George Stark, the fictional author becomes not so fictional and starts killing all those involved with bringing his fictional nature to light.
At first Thad is accused of the crimes, as George and him share fingerprints and blood type, but Thad is cleared due to a strong alibi and the continuance of the murders in New York while Thad is hundreds of miles away.
I am not really sure why this tale didn't resonate with me like King's other works. I think it is perhaps a lack of identifiable characters and a bit of a weak back story and reasoning for Stark's abilities, motives and existence. Had it been any other writer, I am not sure if I would have persevered and finished reading. But as it is, I finished it and I am glad to be done with it.