My feelings on Sherlock have varied to say the best. The first two series I loved, the third I was indifferent and the Christmas Special I had a lot of issues with and ultimately made me worried for series four. The trailer didn’t help much either, making it look more like James Bond than the detective we all fell in love with. Yet, I have to say this series, so far, has had me pleasantly surprised.

If you haven’t seen The Lying Detective (Series 4, Episode 2) or the rest of series four then you might want to stop reading.

So, if you’re still with me you’ve seen the latest episode of Sherlock and encountered Benedict Cumberbatch putting in a stellar performance, alongside guest star Toby Jones who was sensational, a chilling villain to rival Moriarty and actual, real character development and inspection for the first time in four series.

The relationship between John and Sherlock was laid bare for everyone to see in this episode, after the events of the previous week – Mary’s death, John’s guilt and blame shifting to Sherlock – the two were at odds really for the first time in the show’s history. There was an attempt for a similar situation in series three, after Sherlock’s fake death, but it never truly felt like they were at odds. It was obvious that John was going to forgive him, this time, not so much. This allowed the show to really inspect the relationship, that Sherlock actually cares about John and is prepared to go to any lengths to show that. Rather than just being dismissive and cold, like usual, there was a real need. This episode considered what Sherlock would be like without John, the drug addiction (later revealed to be a ploy) felt like a realistic pit for Sherlock to fall into without John. It felt real and perfectly dramatic. Sherlock is an attention seeker, he needs people to know he’s clever and this was something that was played on beautifully.

The characters deconstructed and examined, John’s dabble in debauchery and Sherlock’s humanity which the show had always hinted at but never, for me, truly looked at. Series three insisted on repeating, particularly in the wedding scene that Sherlock loved John, but it never showed it. His actions didn’t truly match his words, especially after it was all he said in the wedding episode, it felt forced and false. Yet, by allowing the characters space and time apart, their relationship grew stronger, deeper.

But the two heroes weren’t the only stand-outs in this episode, Toby Jones deserves a BAFTA for his stunning, sensational and chilling performance as Culverton Smith. It’s obvious who he was inspired by. The charity shots, the idea of money and fame making him untouchable and the creepy, eccentric demeanour all make it clear that Steven Moffat was inspired, as many more people have and will be, by the case of Jimmy Savile. Essentially Jones was playing Savile as a serial killer, but it was more than that. The episode did a lot to get inside the head of a serial killer and attempt to make us understand him. Culverton Smith is one of the most unique villains in TV history and that was made possible by Toby Jones’s portrayal.

The story was incredible, there was no obvious murder, just a villain that the drug-addled Sherlock obsessed over and used to try and get John back in his life. Sherlock doesn’t have a strict format, a case by case process so it can have this kind of freedom and that’s what gives it such potential to be both ends of the spectrum. This was the top end. It followed an episode which I thought was both good and bad, Mary’s plot was never that engaging to me so I struggled with her being the focus. I didn’t understand the need for her to be an assassin, it just felt like an awkward plot point that was thrown in as a big reveal for series three to try and shock people. Mary didn’t have a huge role in the books, so she could be what the show-runners wanted and I think that’s where this series has come into it’s own.

Series one and two were very much in the spirit of the books, if anything they stuck closely to the source material and practically transplanted Holmes and Watson into a modern-day London. Series three is where the deviation began, the wedding episode was something new, for a start, and Mary the assassin was a bid to add originality. Yet, it felt as if the show didn’t know what it wanted to be. New or old, using the books as a basis or reference point. Series four, however, has become its own thing. It still respects the books and the characters, but with Smith and the reveal of Sherlock’s sister, it clearly is moving away from the source material and becoming its own thing.

If this is truly the last series, as many have speculated, I’d be happy. As long as next episode lives up to the high standard, as I did enjoy episode one and have loved episode two, then it’s going out on a high and living up to the standard that it set itself in series one. It’s evolved into its own entity and that would be the perfect end.

In the words of John Watson: ‘It is what it is.’