Series eight of the rebooted Doctor Who has been marked by its deep ruminations on the themes of existentialism and morality as the newly-regenerated Doctor puzzles over who he is and whether he is a good man – questions that are more pertinent than ever following the world-shifting events of last year’s 50th anniversary special.
The penultimate episode is no different with Dark Water centring itself on the question: what happens when we die? It’s a complex theme that is explored in unexpected and ingenious ways as writer Stephen Moffat steps up his game for the first of a two-part finale that is positively thrilling without ever really getting started.
But before we can delve into the twisty-turny matters of life and death we first must answer some of the more fundamental questions that have been raised throughout the series. Firstly, who is Missy?
The character has been teasing us all series with those end of episode stings, leading to intense fan speculation online about who she could be. Last night we finally got our answer as she revealed herself to be the regenerated form of The Master, the renegade Time Lord last played by John Simm in the time of the tenth Doctor, who now goes by The Mistress – or Missy for short – and is back with a new plan to build a master race.
Secondly, just what is the Nethersphere, the administrative hell manned by Missy’s oddball assistant Seb (Chris Addison, clearly enjoying himself as the disturbingly cheery greeter of new arrivals)?
While it initially appears to be a nightmarish cityscape that has been ripped from The Matrix movies, we eventually learn that it is in fact some form of Gallifreyan hard drive used by Missy to store the consciousness of harvested humans while their bodies are upgraded and turned into a burgeoning army of Cybermen.
Yes, the mechanical menaces are back, but not in the way you’d expect. While their presence in the finale featured heavily in the promos, the Cybermen don’t appear fully-formed until the episode’s climax.
This delayed reveal apes The Tomb of the Cybermen with the mechanical monsters hidden in plain sight as skeletons in tanks of dark water, and the creepy build-up makes The Doctor’s most formidable foe feel far more threatening and purposeful than it has in a long while.
Indeed, Moffat’s greatest achievement in this episode is the way he plays with our perceptions. From The Doctor and Clara’s fiery encounter inside an active volcano which turns out to be a dream, to the way we are mislead on Missy and the Nethersphere’s true purposes – nothing in this episode can be trusted to be what it appears.
It makes Dark Water unsettlingly compelling because, like The Doctor, you can sense that something isn’t quite right and the agonizing wait for events to turn nasty is what makes Dark Water a thrilling watch, even though there’s very little in the way of action.
With Missy and the Cybermen keeping their cards close to their chests there’s no active threat here, and much of the episode is spent laying the pieces for next week’s grand finale, all of which means the dramatic focus falls on the main trio.
We all suspected the sort-of love triangle between The Doctor, Clara and Danny would have an explosive end, but the real shock is that the Time Lord has almost nothing to do with the destruction of his companion’s relationship.
Instead, it’s a twist of fate that tears them apart as Clara prepares to admit the truth to Danny – she’s even got a flow-chart of post-its just in case she forgets anything – only for the phone call to be cut tragically short when Danny is struck by a car and killed.
This huge event provides some challenging material for the main cast and Jenna Coleman is once again excellent as Clara, pulling her character through the numbness of grief into vengeful determination and finally despaired strength as she tries to let Danny go.
But it’s Samuel Anderson who really excels as Danny. Finding himself trapped in the Nethersphere following his accident, we’re given a much deeper insight into Danny’s character with two powerful scenes as the former soldier first tries to make amends with the boy he mistakenly killed in Afghanistan and then in a tearful farewell with Clara. Anderson brings an emotionally wrought energy to every scene and it’s a shame he didn’t get to show such range more often during the series.
Michelle Gomez is also superb, playing the unhinged Missy with a twisted whimsy and dangerous spark that feels like a cross between Mary Poppins and Cruella de Vil.
It’s hard to give the episode a final verdict as it doesn’t really have an ending, closing on a tantalizing cliff-hanger as the Cybermen escape into a bustling London, but Dark Water is a triumphantly compelling set-up that raises as many questions as it answers and features fantastic performances all round to make the wait for next week’s extended finale that much more agonising.
Click here to watch Doctor Who: Dark Water on BBC iPlayer