What do we know about Sherlock’s Mary Morstan?

Feature Louisa Mellor 8 Jan 2014 - 12:00

Ahead of Sherlock’s series 3 finale, we tot up what we know so far about this version of Mary Morstan. Speculation ahoy...

Warning: contains plot details for The Empty Hearse, The Sign Of Three and potentially spoiler-y speculation for His Last Vow (which we haven't seen yet).

Something bad is going to happen in Sherlock. How could it not? The Sign Of Three was so cockle-warming an outing for Holmes and Watson, with such a cheering resolution (a baby! a disco! so many declarations of love!), that it had to be setting us up for a fall. A figurative one, this time.

Sherlock’s indestructibility established, the ‘something bad’ dangles Damoclean over other heads than his. There’s John of course, Mycroft, Molly, Lestrade, Mrs Hudson and the Woman, all of whom mean something to us and our hero. Another character though, one whose arrival could have signalled disruption and resentment but whose warmth, humour and winning portrayal by Amanda Abbington meant she ruffled not a feather, feels less safe.

We know so little about Mary Elizabeth Watson (née Morstan), a character imported from canon who clicked instantly and perfectly into Sherlock’s mechanics. If an axe is about to fall on the head of one of Holmes’ inner circle, first it’ll have to slice through the question mark hovering over Mary’s. If either, is she victim or trap?

The window for speculation about her place in the series three finale will have closed come Horlicks time on Sunday, so let’s take this fleeting opportunity to tally up what we know at this point about Sherlock’s Mary Morstan…


She’s a clever, romantic, short-sighted, size 12, cat-loving, disillusioned Lib Dem-voting part-time nurse and only child who reads the Guardian, has a secret tattoo and an appendix scar, bakes her own bread and is both a linguist and a liar.

These all being deductions of Sherlock’s, we haven’t been yet privy to their proof (cleverness aside). How often, though, is the man wrong? How Holmes ascertained the existence of both tattoo and appendix scar on a fully dressed woman is a poser, but no more so than how he deduced her political disillusionment and lack of siblings. Anyone fancy a go at reverse-engineering those conclusions?

The most intriguing of these text-on-screen deductions has to be “liar”. We’ve seen Mary capable of light subterfuge with the imaginary ‘Beth’ code word and separately manipulating John and Sherlock to pair up on a case in The Sign Of Three. About what else though, and to whom, has Mary lied?


She first popped up on John H Watson’s blog

The tie-in blog that runs alongside Sherlock has gone to the trouble of creating fictional comments underneath John H Watson’s crime-solving posts. Mary’s first appearance in the universe of the BBC show came in these very comments. On the in-show date of the 20th of April, Mary replied to John’s comment that he just has to “keep going” during his grief with the reassuring words “And you will x”, quickly followed by “Let’s go for a drink later”. John’s as-yet unseen sister Harry, immediately replied, “Who’s Mary???”.

Who indeed?

From “Let’s go for a drink” to a marriage proposal in under six months is fast work by most people’s standards (though, it should be said, the pair took it slowly in comparison with Watson’s proposal in the Conan Doyle story that introduced Mary, The Sign Of Four).

Other comments from ‘Mary’ on the BBC tie-in blog include words comforting John from trolls insisting Sherlock was a fake, expressing relief that John shaved off his moustache, and berating him for commenting that the Mayfly Man’s date-‘em-and-disappear MO was a “good trick”. She also appears in the blog posts themselves, tagging along once on a case and inspiring these words from the series’ John Watson:

“Oh, and in other news, I've got engaged. But, it's not something I'm really going to talk about much here. I want to keep some things private. I will say, though, she's the best thing that's ever happened to me. Sorry, Sherlock :)”


She’s the best thing that's ever have happened to John Watson

John thinks so, Mary agrees, Sherlock, with the line “Mary, when I say you deserve this man, it is the highest compliment of which I am capable” even allows that Mary Morstan is good for John, and the fans concur. Amanda Abbington’s Mary is warm, funny, clever and very welcome addition to Sherlock’s gang.

If there’s any justice in the fictional world, come the close of His Last Vow, none of that will have changed. Whatever role Mary plays in the series three finale, pray that her essential goodness or love of John isn’t called into question. She may have secrets (more on that below), but we don’t want this version of Mary to go anywhere.

(Besides, if Mycroft knew at the drop of a hat which restaurant John had booked in The Empty Hearse, he’d surely have the low-down on any possibly threat mysterious Mary or her connections could pose to John or Sherlock.)


She’s an orphan

“You need to work on your half of the church, Mary. Looking a bit thin”, said Sherlock in The Sign Of Three. “An orphan’s lot” Mary replied, “Just friends. Lots of friends.”

In the course of solving The Sign Of Four, Conan Doyle’s Holmes revealed to Mary that her missing father was in fact dead, technically making her an orphan (for more on adult orphans, see The IT Crowd’s Roy in Italian For Beginners). When and in what circumstances did Sherlock’s Mary lose her parents? Did she ever know them? Who brought her up?


She knows when Sherlock is fibbing

Nursing and bread-baking aren’t Mary’s only skills, she’s also shown a keen knack for distinguishing lies from truth, and an insight into human nature (about which Sherlock, as it’s been established, knows precisely nil).

As well as intuiting  that Sherlock’s plea to Major Sholto had worked and there was no need for John to break down his door in The Sign Of Three, Mary also told Holmes “I’m not John, I can tell when you’re fibbing”, a talent that could yet prove key to the events of His Last Vow.

(Incidentally, we hope it’s not a clue that when lovely Mary does the thumbs up in the above picture, she’s framed in the shot as if she has devilish horns…)


She’s pregnant

“I’ve never made a vow in my life and after tonight I never will again, so here in front of you all, my first and last vow. Mary and John, whatever it takes, whatever happens, from now on I swear I will always be there, always, for all three of you.” With those words Sherlock Holmes, human Clear Blue stick, announced that John and Mary were about to become parents, and to a real baby instead of a high-cheekboned high-functioning sociopath this time.

Sherlock leaps forward in time as suits the story, so how pregnant Mary will be in His Last Vow, or indeed, whether she’ll have had the baby by then, is all still to know.


She’s a code-breaker

“Save souls now, John or James Watson…” began the text message that Mary quickly identified not as bible spam, but “a skip code” in The Empty Hearse, sending her off to Baker Street to make Sherlock Holmes drop his chips.

The speed of Mary’s code-breaking fits with Sherlock’s deductions of her cleverness and linguistic skills (she recalled Major Sholto’s room number before Sherlock did in The Sign Of Three, too), but perhaps the more interesting question is why the text message was sent to her, and not to Sherlock? After all, John was kidnapped from outside 221B Baker Street, not from his own house or surgery. The taunting messages continued to arrive on Mary’s phone, but were soon addressed to Sherlock, meaning that the person responsible for the kidnap was watching the rescue attempt.

That somebody, we assume, was the villain glimpsed reviewing video of John’s rescue at the end of the episode, the identity of whom Sherlock professed not to know. We know it was Charles Augustus Magnussen (Lars Mikkelsen), the BBC Sherlock’s version of C.A Milverton, heartless blackmailer extraordinaire from the Doyle stories. Something in the next entry suggests that Mary Morstan is no stranger to Magnussen…


She may have had previous dealings with Charles Augustus Magnussen

This one is indebted to the commenters who pointed out a detail from The Sign Of Three that passed me entirely by on first viewing: the wedding telegrams.

A punch line in themselves for forcing Sherlock Holmes to suffer the indignity of reading aloud the words “big squishy cuddles”, the telegrams appeared to contain an allusion to the villain we’re expecting to meet in His Last Vow, the aforementioned Magnussen. If you’re up for a quick re-watch, start iPlayer at around 19:40 in the episode and watch Mary’s reaction as Sherlock reads out the telegram from “Cam”.

See it? Mary is visibly perturbed by the message, which seems innocuous enough (“Mary, lots of love poppet. Oodles of love and heaps of good wishes from Cam. Wish your family could have seen this”). Anyone noting her momentary distress on hearing the name, including John, can tell themselves it’s just an emotional day, but what if - as canny commenters have suggested – Cam is in fact, C.A.M, or Charles Augustus Magnussen?

What hold might the legendary blackmailer have over Mary? We await His Last Vow to find out.

His Last Vow airs on BBC One on Sunday the 12th of January at 8.30pm. Read our spoiler-filled review of The Sign Of Three, here.

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Is she Moriarty after extensive reconstructive surgery?
(yes I'm saying, Is she Andrew Scott?)

You had me at "Horlicks Time"...

How much damage did that bullet do?!

In the Granada Television adaptation of 'Charles Augustus Milverton', CAM on the fly leaf of a book of poetry is a clue to the identity of 'The Master Blackmailer' (the title of the expanded adaptation.

I'm no expert but I'd assume some kind of ricochet down to the man regions, OR (and it could explain a lot about Moriarty) he was a woman all along!

Suddenly I'm feeling more hopeful about this current series. It had been a bit lacking... somewhere, something. Too much epic. Too much Dark Knight. Not enough mystery.
But if it all ties together in any of the ways you've intimated this series may be redeemed.

CAM. Devil.

Trying to find a skip code in his Telegram....Failing :(

I'd do her.

I fully expect Mary to be dead by the close of the 3rd episode or this series.

The last vow proclaimed at a wedding is 'Till Death Do Us Part' - just saying....

I hope not :(

take away the O, R, I and T (anagram of RIOT, as in what's going to occur when this is revealed, or possibly of TRIO, i.e. the TRIO of third season episodes, suggesting a reveal in episode 3, or possibly OR IT, which just needs an apostrophe and an S - filled in by Sherlock, perhaps? - making it OR IT'S, i.e MORIARTY OR IT'S...), and what do you get?

I hadn't really considered that but yes that would make sense. It's not very cannonical but as Sherlockian purist I can live with this diversion. It's too great a development too nag about canon. Were it too happen that is.

We're through the looking glass people.

I appear to have missed a trailer for His Last Vow...

The whole thing is a setup and the look on her face at "Cam" suggests she's not a willing part of it. I suspect Magnussen is threatening her family.
You really have to look at how suspiciously perfectly she has fit in, appealing to both John and Sherlock. Almost profile matched.

I hope you're wrong, but I've had a bad feeling about this all series...

Incidentally, Sherlock knowing nothing about human nature doesn't really stand up. Knowing that a couple"s relationship is on the way out because she's wearing uncomfy underwear and hasn't removed lint from his shirt??

About what else though, and to whom, has Mary lied?..About liking John's moustache. It wasn't even being grown for Movember.

She recalled Major Sholto’s room number before Sherlock did...she stopped off at the hotel reception to ask before joining Sherlock and John.

The telegram from “Cam”...David Cameron sent a card!

Well remember that in the original stories (erm Spoiler..?) Mary Morstan dies - ok the timeline is different and Watson was only engaged to her at the time of the Final Problem (where Holmes 'dies') and she had passed away before Holmes returns in The Empty House. Watson then marries again (twice) but neither wife is named and are only briefly mentioned.

So could this be this Mary's fate? I'm thinking it might be...

Also I would recommend everyone to listen to the BBC Radio Sherlock Holmes version of The Empty House - the shows that emotion was shown in Holmes before this version of the Holmes stories too. The Watson / Mrs Hudson conversation about Mary's passing would make a tear trickle down the cheek of anyone...


By that logic take away the M, O, A, R , T and Y then add a C, H, I, E and C and you get


So Richie C was Andrew Scott all along?

NOW IT ALL MAKES SENSE (*has flashback of every time Richie C mentioned Andrew Scott and puts it all together with dynamic on-screen text accompaniment*)

If I'd read this article an hour ago I might have saved myself the price of dinner in payment of a lost bet. As it is, I'll just have to hope that after Sunday's episode Mary is in no way considered 'bad', proving my wager a sound one!

Have you ever seen Andrew Scott and RichieC together at the same time? It explains a lot.

Andrew Scott is RichieC, RichieC is Andrew Scott.

...tax return?

Note to self - if Richie C invites me to a deserted swimming pool in the middle of the night, bring backup.

Does RichieC have Stayin' Alive by The Bee Gees in his iPod?

He definitely doesn't like it if you crease his Westwood.

Extortion would be fitting for this particular villain. My guess is that he might be threatening to reveal to John something sordid from her past, so that she'll somehow deliver Sherlock to him.

I do!

I knew that if I kept posting that question one day I'd be right!
(Although it's probably not today!)

Of course Andrew Scott being RichieC is news to RichieC's wife but he did say she went away recently. He later claimed it was a conference but it could all be in his mind (palace).

Be surprised if this doesn't follow the plot of the original Conan Doyle story - although Mary isn't in it, someone who could easily be her murders the blackmailer, CAM! I think she is being blackmailed and will get her revenge on CAM. She will murder him which will have huge ramifications for Holmes, Watson, Mycroft, et al. She will either go to jail for the murder (making her a mum behind bars!) or Holmes will honour his 'last vow' and take the rap. Either way, Mary is in trouble!

I assume that it might be too good to be true for John.


I hope she doesn't die because John will feel really empty and devastated. It could also have a huge impact on his friendship with Sherlock, either good or bad...

I reckon she is somehow the master villain, like they did with Irene Adler in elementary

"Wish your family could have seen this"

Odd thing to include in a telegram to someone who is an orphan. I'm leaning towards that the thing mentioned in the article may at least be partially correct.

She gonna die!

It's the restraining order that explains that!

Nice, I really believe there's something fishy going on with her now!

Must say though, I highly doubt she'll be dying. Unless we skip ahead and the baby is now born. I really don't see them violently killing off a pregnant woman. After all, this isn't POPULAR SHOW WHERE THAT DOES HAPPEN.

I've just watched the episode for a 2nd time (recommended, you'll certainly miss some things) and I noticed 2 very interesting moments.

1. Drunk Sherlock. When he's walking about the ghost apartment, there's a very similar goats head. In captions it says "Death. Skull Headed"

2. When Sherlock tells Mary she's pregnant, she's far from pleased, she's actually terrified.
Now first time I saw that, I thought it was Sherlock realising he'll be replaced or (god forbid) a hint that he liked Mary and we were heading for a dreadful love triangle. But it's actually neither of those. He sees how afraid she is and in that moment, behind the cogs, I think he returns to that word "Liar". That's why he walks out looking far from happy, without a word to anyone.

Indeed. Since Mary apparently doesn't have a family to threaten, I'd guess that he's got her by an allegation of somehow having orchestrated her parents' death.
Perhaps she was innocent but the evidence seemed to point that way, and she's been on the run from it since. It would lend a suitably ominous and threatening tone to the last line of the telegram.

You might be onto something here:

THE Woman?

She's one of the few female characters I've seen in a Moffat-involved work that didn't make me want to strangle her. Of *course* she's going to die...

maybe the appendix scar has something to do with it?! the baby? the scar? could be something weird... cant wait for the ep


Is it possible she's actually part of Magnussen's big plan (whatever that is). Somehow knowing that Sherlock was still alive, she was planted by him to get close to John, gain his trust and thereby ultimately Sherlocks. And given her closeness to John she's now in a position to hurt him...and in doing so, Sherlock too, in a way no one else would be able to?

Could explain the look of pure panic on her face when Sherlock announces she is pregnant (as that was never part of the plan) and the 'Liar' trait as highlighted above. Much like when Sherlock was decieved by The Lady to work out what the code meant before passing all the info onto Moriarty back in series 2.

Just a thought...

Yep, probably. MOFFAT!!!!

Is the death of his wife not enough of a reason to be devastated...?
Incidentally, I don't think this will happen in His Last Vow, nor do I want it to.

I think somebody will die but not Mary

I still don't understand why Without a Clue gets so much stick. I find it hilarious on every watch.

Agreed - great concept, great chemistry between Caine and Kingsley...

I haven't seen anyone mention the fact that she had no idea who Sherlock was when he turned up at her dinner with John. He was a famous British detective and John's dead friend. Yet she didn't know what he looked like? Come on! Suspicious Mary is suspicious!

I don't think any of the regulars will die. Molly seems most 'killable' on paper, but then she's got many many fans on the interweb and The Moff & Gatiss know it.

She did know.

Or she is going to die.(Or at least be in grave danger.)

Sherlock is all about Bromance. Mary isn't going to last for long. She's the ultimate disposable woman, the one who can be dumped on and polished off to provide a plot or motivation for the male hero.

I don't think I care what happens.

Did she know sherlock was alive - when she started dating John before Sherl had returned ? Thats really mysterious - she knew he was coming back to John before either Sherlock or Mycroft did. She must be working for Moriarty.

Oh wow this was surprisingly close! You have some sherlock-like deduction skills yourself!

Just finished up my review of the 2-disc DVD release, and developed a wild, unsubstantiated theory of my own regarding Mary:

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