The currently airing tenth season of Doctor Who has been confirmed as the final bow of both Twelfth Doctor Peter Capaldi and showrunner Steven Moffat, and you'd imagine that both want to go out with a bang. To this end, season 10 has been mostly high in quality with a sparkling new companion in Bill Potts - as well as Matt Lucas' hilarious comic relief Nardole - and several fantastic episodes such as "Thin Ice" and the "Monk Trilogy" which showcased new Who at its scintillating, moral-questioning, history-bothering best.
Since the show was regenerated back in 2005, long-running mysteries have become integral to each season's narrative. From the identity of Harold Saxon to the significance of Clara as "The Impossible Girl," these points of intrigue have helped revitalize Doctor Who for a modern audience and provide a thread that ties otherwise standalone episodes together. As season 10 began, it seemed as if the primary question this time around would be what was contained within the ominous vault and how the Doctor came to be its protector at a British university. Without much in the way of explanation, season premiere "The Pilot" finds The Doctor trapped on Earth, duty-bound to look after the high-tech prison with Nardole as his minder and/or butler. Immediately, it is made clear something dangerous is contained within but both characters are careful not to utter a name.
Several teasing clues were laid out for fans to pore over. Mentions of the Doctor's "sacred oath," plenty of loud, repetitive knocking (which pretty much confirmed the eventual reveal) and comments that whoever was inside should never be set free all served to hugely ramp up the mystery of what this cage could possibly contain. Naturally, the fan theories online began in earnest. Possibilities from John Simm's Master or the rumored First Doctor to wackier notions such as the Mondasian Cybermen or the planet Gallifrey were posited by fans intrigued by the show's latest puzzle.
Eventually, in the season's sixth offering, "Extremis," it was revealed that the life form inside the vault was none other than Michelle Gomez's Missy. Having been caught by a group of alien executioners, Missy's mischief had resulted in a death sentence which apparently only another Time Lord can carry out. Cue the Doctor. Not wanting to kill one of his own kind, however, The Doctor promises to imprison and guard the villain, rather than kill her.
Whatever your opinion on this revelation, it's difficult to deny that Missy was the most obvious and predictable contender to be inside the vault, as was the explanation of how she got there in the first place. Even before Michelle Gomez had been officially announced as returning for Doctor Who's tenth season, her presence was more or less expected, as the character has been an ever-present and vastly popular part of Peter Capaldi's tenure. Everyone wanted her back and everyone expected her back, it was merely a matter of when, how and where she would re-emerge.
With Missy as guaranteed an element in Doctor Who as sonic screwdrivers and the word "run," all the enigmatic build up surrounding the vault now seems a tad unnecessary. The show invited fans to speculate, fueled outlandish theories with deliberately vague dialogue and crafted a sense that the mystery would have huge significance later on. But when it came to uncover the truth, Doctor Who went with the answer absolutely everyone could have seen coming before the season even began.
Of course, there are times when taking the obvious route isn't necessarily a bad thing. Back in the David Tennant era, for instance, many fans were already reasonably sure that The Face of Boe was none other than flirting extraordinaire Captain Jack Harkness, but the actual moment of reveal was still hugely satisfying and was also the only option that actually made sense. The vault mystery differs in that there was little point in being so ominous and enigmatic about a character that not only features regularly in the current incarnation of the show but, last time viewers saw her, was working with The Doctor as much as she was against him. Missy's rehabilitation was already in progress.
Another problem with the reveal is how surprisingly low-key it all was, considering how heavily the previous five episodes had trumped up the mystery and threat of the vault. The flashbacks were slipped into "Extremis" almost casually, doing nothing to live up to the ominous tension that had been created. It almost feels as if Missy's presence in the vault was never meant to be a huge secret for the audience, and the mystery element was added at the last minute due to a lack of other season-long plot threads.
This is a real shame because the actual story between The Doctor and Missy in season 10 is - as you might expect - excellent. The Doctor saving his best frenemy from a death sentence, locking her up and attempting to rehabilitate her is a fantastic angle, and one that both Capaldi and Gomez can sink their acting teeth into before they depart. Missy is as eccentric and captivating as ever and the fact that this is her last season on the show adds to the uncertainty of what might occur in the final two upcoming installments. Viewers are still unsure as to whether Missy's remorse is genuine and with a second Master set to feature in the coming final episodes (as well as a Capaldi regeneration) the possibilities for how this final act could play out are genuinely exciting - even without a big mystery to solve.
All of this makes the decision to precede Missy's return with the "who's in the vault" mystery all the more confusing. Arguably, the show would've been better off giving the backstory of Missy's halted execution in the first or second episode, immediately letting fans know that the villain was inside the vault and allowing the story to play out naturally from there. This would have allowed the two Time Lords to take center stage from the start, rather than wrapping the whole plot up in a forced and unnecessary mystery that would ultimately disappoint.
Another way of looking at the situation is that Doctor Who has fallen victim to its own success. The high caliber of long-term mysteries in previous seasons means the show has set itself a lofty standard and when stories fall short of that, disappointment is only natural. Furthermore, the Whovian fanbase is notoriously passionate and wasted no time in speculating over the vault's contents. Perhaps the audience set themselves up for a fall by envisaging something grander than Steven Moffat and co. had ever planned to deliver.
Whether you feel the vault reveal was an anti-climax or perfectly satisfactory, Doctor Who has at least resumed normal service since the mystery was cleared up and looks set to end on a hugely exciting story involving two Masters and the original Cybermen. Undoubtedly a fitting way to send off both Steven Moffat and The Twelfth Doctor.
Doctor Who continues June 24th with "World Enough And Time" on BBC and BBC America.