This series has seen more deaths than usual and even more importantly the appearance of a new character. Missy. This tea drinking spooky Mary Poppins has appeared frequently after a character’s death repeatedly introducing the idea of a “Promised Land.” But who is she?

As said before, in many of the episodes characters have died and then been transferred to Missy’s “Promised Land.” Could this perhaps be Missy collecting lives that were lost as a result of the twelfth Doctor? All these people that are being saved have not been chosen at random, they have been chosen because of their association with The Doctor. But what could the purpose of this be? To make The Doctor realize the deaths he leaves behind? To create some kind of army against The Doctor? Does she want to recruit the Doctor for her army? Perhaps the creation of Danny Pink is meant to convert The Doctor’s views on soldiers. The Doctor’s meeting with Soldier Blue in “Into The Dalek” supports this idea. The series finale trailers have confirmed that the Cybermen will be making an appearance. Will this be Missy’s army?

The mystery of Missy’s identity goes hand in hand with the mystery of the identity of the “Promised Land.” Many fans have been theorizing over what this could indeed be. For example, many fans have made a link between how Missy’s “Promised Land” looks similar to where the older version of Amy was in the episode “The Girl Who Waited.”

Another theory that has came from fans is that Missy is CAL. This character appeared in “Forest of The Dead.” The Doctor and Donna discovered that a little girl’s mind was saving the people into the computer core. Many fans have made the link between how CAL saved people and how Missy appears to be saving people.

Many fans are also hoping for a return of River Song. Whilst this would be greatly enjoyed by all, Moffat has in some interviews hinted River Song will probably (and sadly) not make an appearance.

One of the most outlandish theories for Missy and the “Promised Land” is that Doctor Who is being made into an ACTUAL TELEVISION SHOW. Yes – you read correctly. The synopsis of the series finale reads that The Doctor “takes to the air in a startling new role”. Some fans believe that perhaps Missy is using The Doctor and Clara’s adventures for television entertainment!

One of the most popular theories is that Missy is an echo of Clara Oswald. When Missy was first introduced she called The Doctor her “boyfriend”. Could this be a version of Clara that became insane when waiting for Eleven’s regeneration to one day return? This is similar to the plot of “The Girl Who Waited.” Many fans seem to agree that Missy is linked with Clara somehow. Is Missy a future version of Clara? Perhaps Missy was the one who gave Clara The Doctor’s phone number and the one that put the advertisements in the newspaper? Will Missy be involved in Clara’s departure from the show? The trailer for the finale has revealed a much darker side of Clara. Will she perhaps become an enemy? Is she a creation of Missy? A weapon? We shall soon know!

A final theory is that Missy is a reincarnation of The Master and her “Promised Land” is indeed Gallifrey. The Master last appeared in Ten’s finale and many fans are anticipating an appearance even if its in the form of a different identity.

Although we can spend hours and hours theorizing over who Missy is, I am afraid we will not know until the series finale. All we have been given is that she is the gatekeeper of the nethersphere. Again could she be the gatekeeper of the void that contains the Daleks and the Cybermen. Or perhaps the gatekeeper of the word that belongs to the ghost Cybermen that appeared in the finale of the second series of the reboot. Whether Missy will be a hero, a villain or perhaps neither is unclear, but the synopsis states that old friends must unite with old enemies to defeat the Cybermen. The trailer has obviously raised even more questions and fans are eagerly awaiting the finale, but will be sad when series eight comes to an end.