I don't like this theory that Voq has been surgically modified to look like a human , that is Tyler.

Many poster believe that when L'Rell said to Voq that to win the war he would have to sacrifice everything they thought she was referring to his identity.

I find this a little far fetched ..if this is what really did happen he would still be biologically a Klingon though so a medical check up would reveal his true nature.

.This theory also would suggest that the real Tyler was captured (and maybe later killed) and that Voq surgically modified took his identity . He would have had to learn Tyler's life history and learn English ..too complicated in my opinion.

It is possible though that during the last weeks of his imprisonment ,before Lorca was captured I believe on purpose so both could then escape back to the Discovery , L'Rell used some device to brainwash Tyler ( turning him into a sleeper agent) or maybe worse Voq's mind was transferred into Tyler's and when the time comes Voq's mind will take over leaving Tyler's mind dormant .

I hope the writers go down this path because this way there is still a possibility to save Tyler once the truth comes out...otherwise if Tyler turns out to be actually Voq surgically transformed he will end up being sooner or later killed .

I'm starting to really like Tyler I would be disappointed to see the actor leave the cast .. I like the chemistry between him and Michael and Lorca. I think those three are the most interesting characters .

The flashbacks could be various moments ..bloody scenes :Tyler being tortured,others Tyler brainwashed having sex with L'Rell ...or Voq's mind in control of Tyler's having sex with her.

There maybe a secret word that switches Tyler's mind off and lets Voq's mind emerge and L"Rell obviously knows that word.