Andrew Lincoln says he loves a secret - and that's partly why the British star of zombie drama The Walking Dead has told no one the answer to what has become the show's biggest mystery.
Fans are dying to know what scientist Dr Jenner whispered to Lincoln's character, Sheriff Rick Grimes, in the season one finale.
But former This Life actor Andrew said: "Not even my wife knows what he whispered to me."
Andrew said that in keeping the secret he feels he is being true to his character in the AMC show. "He chooses not to tell people, so why would I tell?" he said of the sheriff.
What was said has only been heard by a handful of people and the mystery has become the object of intense scrutiny by fans.
Andrew said he realised just how curious people were when a show editor revealed he had scrolled through hours of show footage and listened in on radio traffic to find the only two takes where the brief remarks were audible.
The cast says the contents of the conversation will be revealed this season.
Andrew, who says the comments are "pivotal" for Rick, hints that the message was not good news.
"This is a scientist who seemingly held all the cards to what this epidemic is about and I do think, you know, you would imagine he would have something of value to say on that matter," he said. "Well, he chose to kill himself."
The actor also said that Rick and his ragged group of survivors will probably leave the farm where they have taken refuge this season. "Something happens and they realise very quickly that the farm is not as secure as they may think," he said.