"There are certain clues, or plot points, or spoilers, that we literally never write down, in case..."

“There are certain clues, or plot points, or spoilers, that we literally never write down, in case they get out. And I’m often the one who says them. And I just say them on the day. So they’re never present in the script. So that there’s no danger of them being leaked.”

- Mark Gatiss, BBC Breakfast (x)