Caution: Spoilers ahead for Star Trek: Discovery
Is Captain Lorca the real "enemy within" in Star Trek: Discovery? The show has returned from its winter break and immediately set about confirming a theory that has been doing the rounds online for several months: that Chief of Security - and Michael Burnham's new lover - Ash Tyler is almost certainly a Klingon. This revelation neatly tied into a scene that featured spore drive-addled engineer Paul Stamets glazing over at the eyes and claiming "the enemy is here" in his best mad-scientist voice.
With the Tyler reveal occurring simultaneously, the mystery appeared to be a straightforward one. Stamets knows there's an enemy on board, Ash Tyler is a Klingon, case closed, right? Perhaps. While Stamets may well have been referring to Ash, there is another figure on board the good ship Discovery who has been acting suspiciously for quite some time: Captain Gabriel Lorca.
While it's clear that Lorca's agenda is very different to that of Starfleet, viewers have speculated since his first appearance on Discovery that the Captain could actually be from the Mirror Universe - and since his ship landed there in the winter finale episode, this theory has only been strengthened.
It was revealed in "Despite Yourself" that Mirror Lorca was a fugitive who attempted a coup against the totalitarian regime of the Terran Empire and is currently wanted for the murder of Michael Burnham. Not only does this tale provide Mirror Lorca with a motive for crossing universes - where better to run from the law than a parallel world, after all - but it also explains some of Lorca's riskier actions thus far in Star Trek: Discovery.
Blamed for triggering the war between Starfleet and the Klingons, no one in the federation wanted anything to do with Michael Burnham. Lorca, on the other hand, went out of his way to free the prisoner from her secure transport and then offered her a position on his ship. While the Captain plays his actions off as wanting to make the most of Burnham's scientific brilliance, there is likely to be a more selfish motive at play. Assuming that the Lorca currently leading the Discovery is from the Mirror Universe, there's a distinct possibility that his intentions all along have been to secure the other world's Burnham and use her ability to command the Shenzhou to reignite his coup. Alternatively, Mirror Lorca could be planning to clear his own name by showing the Emperor the very person he stands accused of killing.
This explanation would also account for Lorca's blood-stained backstory. One of the biggest question marks hanging over the Starfleet Captain is how he survived the destruction of his old ship, the Buran, when everyone else on board perished. One possibility is that he didn't survive at all, and that Mirror Lorca is using this to his advantage, posing as the sole survivor. Another potential answer is that, traumatized by losing his ship, the real Lorca willingly switched places with his Mirror counterpart in exchange for the more battle-hardened Lorca's help in winning the war against the Klingons.
And then there's Stamets' other foreboding warning: "stay out of the palace." While the exact meaning of this has yet to be uncovered, the most likely explanation is that the "palace" in question belongs to the mysterious, tyrannical "Emperor." If Lorca's true plan is to overthrow Emperor, or indeed to offer negotiate his pardon, Stamets' words would make complete sense: don't enter the palace, otherwise the crew will be in danger.
Add to this the various moments of foreshadowing throughout this season, such as Vice Admiral Cornwell noticing differences in Lorca's body and Doctor Culber accusing Lorca of wanting the Discovery to travel to the Mirror Universe, and it certainly appears that Ash Tyler isn't the only one that Burnham and co. need to worry about.
Star Trek: Discovery continues January 14th on CBS All Access and Netflix internationally.