'Sherlock' season 4 news: show creators talk about their decision to kill off Mary

"Sherlock" started with news that John Watson (Martin Freeman) and Mary (Amanda Abbington) are now raising a baby and things are looking well for them. Unfortunately, it ended with Mary taking a bullet for Sherlock Holmes (Benedict Cumberbatch), and she died in her husband's arms.

Well, "Sherlock" fans knew that Mary was going to die at some point, but no one expected it to happen in the premiere. After a screening of the first episode, show creators Steven Moffat and Mark Gatiss explained (via Deadline) why they decided to kill her off at the beginning of the season.

"We felt this was absolutely the right place to do it. Mary's been dead for a hundred years so it's hard to surprise people in those circumstances. The only thing we could do was do it earlier than people thought — as wrenchingly as in real life," Moffat stated.

Freeman said the scene was difficult because he felt that he had to do it justice, but he doesn't want to overdo it either. "It's a careful line," he explained. He also noted that to act that his longtime real-life was shot was certainly tough. Freeman has recently split up with Abbington, but they remain good friends.

Interestingly, Sir Arthur Conan Doyle never said that Mary died. In "The Empty House," Watson talked about his "sad bereavement," but Doyle did not outright say that Mary was dead.

"It's a strange thing but actually in the original stories it's not actually said that she has died. It's heavily inferred. But it could have been a messy break up," Gatiss said at a screening (via Radio Times). He went on to say that they didn't have to kill Mary off, but they felt that it was the right things to do.

"Sherlock" season 4 episode 2, "The Lying Detective," will air on Sunday, Jan. 8, on BBC One.