After what seemed to be an endless amount of time for the fandom that waited, Sherlock finally made his on screen comeback on Sunday, January 1st, airing its first episode of the 4th series, called "The Six Thatchers". And it's definitely honest to say, it started out with a bang.

While the beginning of the episode sets a funny and lighter tone, with Mary giving birth to her and John's daughter, Rosamund, the christening in which Sherlock, along with Molly Hooper and Mrs Hudson attend as godparents, and the new parents' (and Sherlock's as well) efforts to balance out babysitting and case solving, soon things take a turn to a much darker place, culminating in the heartbreaking loss of dear Mary Watson.

Throughout the episode, there is one theme that seems to be prominent: betrayal. Mary is accused of betraying her former team and one of her collegues seeks revenge. John is betraying his wife by, seemingly, having an affair with another woman. And ultimately Sherlock betrays His Last Vow (an excellent nod to series 3) to protect the Watson family no matter the cost, when his arrogance and need to show off his skill of deduction cost Mary her life.

Mary's introduction in the third series divided the fans to those in favor and those against it, as she was the reason the balance shifted and the dynamic that everyone was used to until then changed. Yet I believe that Mary was a wonderful addition to the Holmes-Watson duo, her witty and easy-going mannerisms with which she handled both men always pleasurable to watch, and her enthralling past that gave her the element of mystery always welcome to the viewer's eye. And I will miss her immensely. I honestly did not believe I would be so heartbroken in case she fell victim to mortality (as it was always insinuated since the original Mary Morstan in Arthur Conan Doyle's novels also supposedly died), but the moment I witnessed John mourning above her lifeless body (an excellent performance by Martin Freeman that one), Sherlock and Mycroft standing by his side shocked at this turn of events, I realised that her loss is not one that I could accept as easily as I thought. Amanda Abbington fell right into Mary's shoes with such smoothness, as if she was always meant to play this particular character, and seeing her go is definitely the hardest thing I will have to endure as a Sherlock fan (yes, harder than having to wait 3 years for a new episode), because I truly and honestly did NOT want to see her go.

The episode also revealed the mystery behind A.G.R.A. as well as Mary's real name and the secret she kept hidden from both Sherlock and John in series 3, as it also included a surprising (and mostly welcome) amount of action the show hasn't seen before. Director Rachel Talalay's extraordinary job lead to jaws dropped on the floor with the knockdown fight in the pool between Sherlock and AJ, the gun fights in the hostage flashback and the showdown between Mary and AJ in Morocco, as well as the incredibly intense final scene in the aquarium. The Sherlock team was always known for its skill and in that regard the 4th series' premiere did not fail in the slightest.

However, I can't lie and say that "The Six Thatchers" did not leave me a bit bitter. When a show is as good as Sherlock is, you can't help but compare each episode to all its predecessors in all aspects. And yes, I am not handling Mary's death that well (but bare with me because it's still raw), but what really disappointed me was John's infidelity. While we never got to see him fully interact with the girl on the bus, the intent is clear from the first moment and it did seem a bit out of character for him to be cheating on the woman he fought so hard to keep into his life, the woman that basically saved him from himself when he thought his best friend was dead and gave him a precious daughter and a new life. Yes, we all know that Watson is a "ladies man", but he is also kind, honorable and faithful to those he loves. Betraying Mary in that way did seem out of the blue, so I'm very interested to see how the show will cope with that in the remaining two installments.

On the other hand, I find myself truly enthralled by this new, emotionally evolving Sherlock. Seeing Mary take a bullet for his sake, giving her life to save her friend, must have been one of the most breaking experiences of his life, leading him to seek professional help in order to cope. We've seen Sherlock take small steps into what he considers to be humanity's biggest weakness, human emotion, since series 2, but this is new territory he steps into. A more human and less emotionally detached Sherlock is a Sherlock I cannot wait to get to know and I'm most certain Benedict Cumberbatch is going to bring us to tears with his performance. Where will series 4 take him? We only have 2 more episodes to find out.

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