Imagine if John F Kennedy had lived... Ahead of the 50th anniversary of JFK's death Stephen King introduces a special extract from his novel '11.22.63'

In his novel 11.22.63, Stephen King writes an account of the build-up to the assassination of John F Kennedy, and an attempt to prevent it from happening. Terminally ill Al Templeton has found a portal to the past in the pantry of his diner. He has convinced his friend Jake Epping of its existence by sending him through it to 1958. When a shaken Jake returns, Al tries to persuade him to go back and finish the job that Al himself couldn’t – to stop Lee Harvey Oswald. But will Jake grant the old man’s dying wish? Could an ordinary English teacher from Lisbon Falls, Maine, do it even if he wanted to? And how would history change if he did? Here, ahead of the 50th anniversary of the death of the president, the best-selling author introduces a special extract…