Doctor Who series boss Steven Moffatt has blasted fans who leak details of plots, accusing them of "vandalism".
He spoke out after the entire plot of a two-episode opener to the latest run of the BBC1 show was posted online prior to broadcast.
Moffatt, the creative force behind the show and its executive producer, said the shows depended on shocks for their success.
He told BBC Radio 5 Live: "You can imagine how much I hate them. I wish they could go and be fans of something else."
It is thought those who gave away the plot had been invited to a preview screening but had been specifically asked not to blow the plotline. However they were posted online shortly afterwards.
"It's heartbreaking in a way because you're trying to tell stories, and stories depend on surprise," said Moffat.
Most fans of the Time Lord went out of their way to avoid having the plot ruined in advance, he said.
"They want to preserve the surprise," he said. "The tragedy is you have to work hard at that now."
Moffatt continued: "Stories depend on shocking people. Stories are the moments that you didn't see coming, that are what live in you and burn in you forever.
"If you are denied those, it's vandalism."