Mark Gatiss' latest script struck me as 40 minutes in search of its admittedly impressive final minute. In that regard it was cut from the same cloth as many of Gatiss' other episodes of Doctor Who: a cute notion, a striking visual sell or - in one case - a smart-arse title.
The polymath writer has tended to produce rather shoddy episodes that have strong concepts at their core but either devolve into pastiche or simply fizzle out. Of his eight scripts for the series few would suggest that, beyond The Unquiet Dead and The Crimson Horror, there's much to commend them.
I quite enjoyed Sleep No More, though I wasn't giving it my undivided attention. In its own right it was a very average runaround (the word 'romp' is forbidden in these parts) with a found-footage device, Moffatian monster and nonsensical twist. At times it reminded me of Night Terrors - in that it was the only other time since Doctor Who returned when the production felt lacking.
From the blank-slate supporting characters (making someone say 'man' and 'pet' every other word is not characterisation), some very wobbly acting and some confusing direction, Sleep No More felt decidedly wonky at times. The plot, if described, is hardly convoluted yet it wasn't always clear what was going on during the episode and some of the dialogue was wince-worthy.
Worst of all, though the final reveal was the most atmospheric part - and was of a sufficiently Vine-able, GIF-able nature to send a few chills around social media and watching kiddies - there seemed to be absolutely no point whatsoever to it, as Reece Shearsmith's Gagan Rasmussen admits.
To have the Doctor repeatedly stating that nothing in the narrative made any sense - something known as lampshading - only adds to the suspicion that the episode was written around the very same conceit that ends Ghostwatch. Lose it and the whole thing was, by definition, pointless.
Does that mean there were not moments to enjoy? No, but it does make Sleep No More once of the shonkier, more disposable episodes this season. An unreliable narrator, a first-person shooter directorial style, a enormous twist that almost takes a pot-shot at our predilection for watching things we shouldn't and a very bad Geordie accent (literally no-one in the north-east calls everyone 'pet' - in fact I'm one of the view few who calls anyone pet) and it's all a bit of mess.
Throw in two of Steven Moffat's greatest hits - the corner of your eye trick from The Eleventh Hour and the angel is Amy's eye in The Time Of Angels - plus a handful of sci-fi and horror tropes and Sleep No More adds up to a very odd episode that, like most of Mark Gatiss' efforts, really doesn't quite feel finished.
This is the third time in one year where the title sequence has been messed with for reasons that don't feel like much more than desperately trying to do something different with the damn show. It's a touchstone in an episode where a shedload of ingredients are hurled at the wall in the hope that no-one notices the paucity of whole.
And that - of the most part - is Mark Gatiss' contributions to television Doctor Who summed up. He really should adapt Nightshade.
Watching The Zygon Invasion reminded me that Paul Cornell once wrote that the Third Doctor in a Prisoner-Of-War camp would be 'sour'. Yet he also argued that the Seventh Doctor in that environment would not be. His reasoning, I guess, was that no writer could sustain something as artificial a construct as the Third Doctor - with his 'mother hen' and UNIT family and going cross-eyed when in danger - within a setting as real, visceral and sensitive as a pogrom.
In The New Adventures - a series that contained racism, sex, swearing and everything in between - the tone could support a deeper, darker level of material. I may not agree with Cornell, but I can see the point. There has to be an envelope in which the series exists - push too far in different directions at the same time and the whole thing becomes uneven, uncomfortable, perhaps inadvisable. Sour.
Yet in The Zygon Invasion we got precisely that: the nightmare scenario. A Doctor that plays his own theme tune on an electric guitar one week; plays hide and seek with a character out of a two Ronnies sketch another and in the next he battles terrorists who converse in the same language and medium of people who are - right now - slitting the throats of people they judge to be different from themselves.
A story that has our hero advising a UNIT commander that her troops should 'try not to kill all of them' and has Kate Stewart surveying industrial bins full of human bodies. In a series whose tone isn't wildly out of kilter with the stuff you can see on CBeebies and also contains references to Isis execution videos. It's a show that can wave around words like 'radicalisation' and 'funkenstein' within minutes of each other.
The general irrelevance of the Doctor to the plot was instructive. Instead we got people designed to be relatable, believable, because in the world of The Zygon Invasion the Doctor strikes a sour note. We cannot ever square the man from The Daemons, City of Death, The Five Doctors, Time and the Rani, New Earth, The Crimson Horror with this Doctor.
That's what Paul Cornell was talking about: he was wrong to say that solely the Third Doctor - played by a man, lest we forget, who served in WWII - could not enter into certain fictional spaces. But he was, I think, right to suggest the Doctor cannot and should not move in some fictional spaces because whatever happens the show will always have a high level of absurdity.
It's always been there in the series' texture; in recent years the childishness of Doctor Who has been ramped up to 11. When it's mixed with the kind of gruesomeness we saw in Dark Water or an atrocity allegory the whole concoction curdles.
What we saw in The Zygon Invasion was Doctor Who Meets The Taliban; An Exciting Adventure With Muslim Extremists. Despite the direction, acting and even Murray Gold managing to keep a lid on his usual histrionics, we had something that some people sensed was... wrong. Sour.
Steven Moffat may believe Doctor Who has moved beyond tone. To me The Zygon Invasion was evidence of a programme that has slipped its moorings. It no longer knows what it is or who it is for.
Doctor Who now operates on a level of its own. It's setting its own rules. A programme that simultaneously mines the depths of day-glo stupidity and visceral everyday horror. The Zygon Invasion demonstrates that it no longer operates as parody nor pastiche. In modern Doctor Who the only question is 'should we go there?' and the answer is always 'yes'.
Watch it here on iPlayer