Spoiler alert: do not read unless you have watched Sherlock series four episode three, The Final Problem.

Now that The Final Problem has been solved, and Eurus has calmed down about not being hugged much as a child, and Sherlock and Watson are running side by side towards – if I read their facial expressions in last night’s final shot correctly – the nearest Imodium stockist, it’s time to look back on this series of Sherlock as a whole. Did it work? Was it worth the wait? Does the BBC owe the Crystal Maze some sort of royalty cheque now?

For me at least, the answer to all three questions is “probably not”. The Final Problem won’t go down as the most self-satisfied episode of Sherlock – that’s still the one where Sherlock got bored at a wedding and pottered around in his mind palace until the credits kicked in – but it was nevertheless the final flourish of a series that didn’t seem to know what it wanted to be.

Of the three episodes to air this year, two began with mealy-mouthed semi-apologetic explanations of plot holes from the previous episode. Remember when Sherlock shot and killed Charles Augustus Magnussen at the end of His Last Vow? The Six Thatchers opened with characters literally editing that murder out of history. And remember when Eurus shot John Watson in the face with a gun last week? Remember what a cliffhanger that was? Turns out, thanks to a shrugged-off oh-well-never-mind half-line of dialogue early on, it was just a tranquilliser gun. Ho ho, never mind. That’s Sherlock.

If they can promise there’ll be no more annoying Saw rip-offs, or scenes where Sherlock karate-chops a coffin in anguish, I might come around to Sherlock again. Photograph: Laurence Cendrowicz/BBC/Hartswood Films

If there is to be another episode, and that’s far from certain at this stage, you can guarantee that its first scene will be a quick bulletpointed go-over of all the plotholes and missteps of last night’s episode. Sherlock and Molly’s relationship will be back to normal, the trauma of their phone call absent-mindedly waved away. John will uncover the mystery of how Mary managed to make such a very long DVD without him ever finding out. And perhaps, just perhaps, someone will point out how Eurus escaped from her maximum security island prison for long enough to pose as both a therapist and the daughter of a noted serial killer – and to have a full-blown text affair with John – and get back again without anyone noticing.

On the plus side, at least this series clarified that Moriarty is definitely dead. Hopefully, should there be more of this, he’ll never be mentioned again. Hopefully Eurus has supplanted him as Sherlock’s worthy nemesis and we won’t have to watch him infuriatingly goon about like the third understudy in a touring regional theatrical adaptation of Jim Carrey’s The Mask. At least there’s that. If we can have similarly definitive promises that there’ll be no more annoying Saw rip-offs, or scenes where Sherlock slow-motion karate-chops a coffin to pieces in anguish, I might find myself coming around to Sherlock again.

Steven Moffat and Mark Gatiss have claimed that their Sherlock Holmes has now reached the point where he can suitably be compared to Sherlocks of television past. He’s been tested and broken and humanised so thoroughly that he now bears little resemblance to the sexy young swishy-coated alien from the pilot. He knows Lestrade’s first name. He’s helping to raise Watson’s baby. He’s a wise old mastermind with a functioning set of emotions, and now he can stand shoulder to shoulder with Jeremy Brett or Basil Rathbone.

If that’s the case, then good. Sherlock sorely needs to snap back into a recognisable shape. The Final Problem felt like the outer orbit of Sherlock. It felt like it came from a place so utterly divorced from what it ever was, that it’d be a blessed relief if the next episode was just a meat and potatoes mystery caper. Wear the hat, play the violin, solve something impossible. Sherlock has become a parody of himself. It’s time for him to become Jonathan Creek again.