Spoiler Warning: This post contains spoilers for Agents of S.H.I.E.L.D. up to episode 6 of season 3.

This past week’s episode of Agents of S.H.I.E.L.D. had a reveal that will turn the show upside-down. With word getting out that Andrew Garner is actually Lash, the whole team is at danger. As of right now, May is the only one to know about his dual identity and in the newest clip (via IGN), she decides to confront him before the news manages to get out to the others.

Blair Underwood, who plays Andrew, recently spoke to E! News about making the transformation, how he found out, and more. To start, he was surprised just how many fans figured it out before the reveal.

I have to say, I am shocked that after that last episode aired two weeks [ago], all my friends started sending me all this “#AndrewIsLash” and all the theories of why Andrew could be Lash and how spot-on some of them were. But, if you look at his work as a psychologist…in S.H.I.E.L.D., he determines [who] is worthy and is not worthy to be part of the Secret Warriors team that he’s to create with Coulson. So, it makes sense that it’s kind of that same kind of rationale, but on steroids: Who’s worthy and who’s not? And what are they worthy of? Are they worthy of life? Are they worthy of death? Are they worthy of the team? Or are they not worthy of anything?

He also talked about how he found out about his character’s transformation during his birthday – back in August! For Underwood, he’s glad that it’s finally out as he’s been holding it in since then.

I am very much relieved…I feel like I’ve been holding this secret for a month, two months now. You know what, it’s two months because I found out on my birthday, August 25, at the table read. I remember it because, when we read the script where it looked like I’m dead, episode four, the producers said, ‘Well, let’s take a minute and come back in the office. We’ll tell you what’s happening with the character.’ That’s when they told me that Andy is Lash and I said, ‘You know what? That is, like, the best birthday gift I could’ve gotten.’

As for as how and when he became Lash? Underwood says we should know the answer to that shortly.

Without giving anything away, you’ll see in subsequent episodes an explanation of how he became Lash and how he feels about it. It’s very complex.

This needs to be a good explanation as it’s unclear when he transformed and how it happened. I’m guessing it’ll be caused by the fish oil to tie it back together, but it would also be interesting if he has always had this power, but he didn’t need to use it until now.

Agents of S.H.I.E.L.D. airs every Tuesday on ABC at 9 p.m. EST.

Sources: IGN and E! News