Fans had long held the theory that Ash Tyler was actually Voq, surgically altered to appear human.
At first refusing to help Ash/Voq, L’Rell revealed more about how the Klingons turned Voq into Ash Tyler: There really was a Starfleet Lieutenant Ash Tyler who was captured at the Battle at the Binary Stars.
Star Trek: Discovery streams Sundays @ 8:30pm ET on CBS All-Access, in Canada on Space Channel, and worldwide on Netflix.
Ash Tyler is really Voq, and Ash/Voq made that clear to Michael Burnham before she had him seemingly executed on board the I.S.S. Shenzhou.