Star Trek: Discovery has confirmed its biggest fan theory is true.
SPOILERS for Star Trek: Discovery "The Wolf Inside" follow.
Fans have theorized that Ash Tyler is actually Voq since the show's earliest episodes. "The Wolf Inside" showed that they were correct.
In last week's episode, Ash Tyler seemed to be fighting a revelation from within himself. Tyler visited the L'Rell in the brig. L'Rell implied that there is a deep, loving connection between the two of them. She then spoke a prayer in Klingon. Tyler responded in Klingon then blacked out. L'Rell became confused. She said prayer should have worked but that something is wrong.
Tyler then visited sickbay to speak to have Dr. Culber run tests on him. Culber discovered evidence that the Klingons altered Tyler. He bears the scars of an appearance-altering surgery. They also tampered with his brain to contain another personality. Tyler panicked and snapped the doctor's neck.
Tyler was able to flee from his crime by joining Burnham on the ISS Shenzhou. He joined her as part of the away team that met with the Firewolf's rebels. It turned out that the Firewolf was Voq.
Seeing Voq made Tyler uneasy. Hearing Voq speak of his resistance alliance between races set Tyler off. Voq's rebels included Vulcans, Andorians, and Tellarites. These are all races that T'Kuvma preached against. Tyler had flashbacks to those preaching and attacked mirror Voq. Mirror Voq defeats Tyler and only spares his life because Sarek intervened.
Upon returning to the Shenzhou, Burnham questioned Tyler. Tyler's memories of being Voq returned. He remembered the matriarchs of House Mo'Kai transforming him into a human. He remembered fighting Burnham on the deck of the Ship of the Dead. It all came back to him and he attacked Burnham. Mirror Saru, Burnham's slave, saved her.
Tyler remained defiant. When faced with execution, he asked in Klingon for Kahless's light. Burnham ordered him beamed into space, but alerted the Discovery. The other ship beamed Tyler back aboard, where he was to imprisoned. A trial awaits him when and if the Discovery returns home.
New Star Trek: Discovery episodes become available to stream Sundays at 8:30 p.m. ET on CBS All Access.