Sherlock creators Mark Gatiss and Steven Moffat on why that shocking plot twist had to happen

SPOILERS: Fans were left reeling after a tragic finale to the series four opener




So Mary Watson is gone, shot by double agent/receptionist Norbury while heroically protecting Sherlock from a bullet. 

But why did John Watson’s beloved wife, the mother of their new baby daughter Rosamund, have to die? How could Sherlock creators Mark Gatiss and Steven Moffat be so cruel?

One answer lies in the source text, in which a throwaway line is generally interpreted as confirmation that Dr Watson’s wife has passed away. 

In in the following passage from Sir Arthur Conan Doyle’s story The Empty House, Watson reports his friend Holmes’s allusion to “my own sad bereavement”.  

“In some manner he had learned of my own sad bereavement, and his sympathy was shown in his manner rather than in his words. ‘Work is the best antidote to sorrow, my dear Watson,’ said he; ‘and I have a piece of work for us both to-night which, if we can bring it to a successful conclusion, will in itself justify a man’s life on this planet.’ In vain I begged him to tell me more. ‘You will hear and see enough before morning,’ he answered. ‘We have three years of the past to discuss. Let that suffice until half-past nine, when we start upon the notable adventure of the empty house.’”

According to Gatiss, who wrote fateful series four opener The Six Thatchers, the ambiguity in that passage means Mary could feasibly have lived on in BBC Sherlock but that he and Moffat had known for some time that they would kill her off – and even the basic how and why.

“It’s a strange thing but actually in the original stories it’s not actually said that she has died,” said Gatiss at a screening of episode one. “It’s heavily inferred. But it could have been a messy break up. We have obviously been true to Doyle and also very untrue. So we didn’t necessarily have to do this, it just felt actually the right place to do it.

“It was definitely going to be saving Sherlock. We did an early road map without any details.”

Moffat said that since most Sherlock Holmes fans believe Mary did die in the books, they were expecting it to happen at some point but that it was seen as more likely to be a cliffhanger at end of series. So to do it early was he and Gatiss’s best chance of surprising viewers.

“Mary’s been dead for 100 years so it’s hard to surprise people in those circumstances,” said Moffat. “So the only thing we could do was do it earlier than people thought. So that it would happen as wrenchingly and as horrifically as such things happen in real life, so that’s what we went for.”

It also helped bring things full circle, he said, after Mary had threatened Sherlock’s life by cold-bloodedly shooting him in the finale of the previous series.

“Obviously we had the thing hanging over us that Mary and Sherlock were very close but there was that moment of froideur when she shot him in His Last Vow so it was nice to reverse that and have him save her life.”


The next episode of Sherlock, The Lying Detective, is on BBC1 on Sunday 8th January