As Netflix dropped the second part of the eagerly-awaited fourth season of You, Tati Gabrielle has opened up on what it was like working with Penn Badgley.
The actress, 27, insists the star of the show morphed into a "whole new person" while filming the hit series, especially during tense scenes.
Tati, who played Penn's character Joe's love interest in season three was seen in early episodes of the new series desperately trying to evade her kidnapper on the streets of Paris.
And discussing her role in the third series she confessed she will "never forget" the pair's first scene together.
Speaking to PEOPLE, Tati said: "We were talking Penn and Tati, and then they got ready to call action, and Penn's eyes changed. Just a whole new person stepped into his body. And I was like 'Oh my God. He's so good'."
She continued: "He started doing these scenes, and Joe, in this dissociative state, it was sort of doubling anxiety-inducing because, on one hand, Marienne is desperate to get through to Joe.
"He knows that something's happening mentally speaking, and she's trying to pull him back out. And then on top of that, as Tati, I couldn't feel Penn anymore."
But she labelled this ability a "testament" to his talent, saying his skills made for much more "authentic" moments in front of the camera.
With fans able to now binge watch the latest series all at once, Penn, 36, has promised "twist after twist" in the latter episodes.
Speaking to Holly Willoughby and Phillip Schofield on This Morning on Thursday, he said he wouldn't give away any spoilers but could say: "The twist you think you're waiting for in part two, it happens almost right away, it happens so soon.
"Then there's another twist, then there's another twist and by episodes nine and ten you're like 'what is happening?'"
Despite his character Joe's seeming need to fall for women at the wrong time, with viewers going on his love journey with him, Penn did previously reveal he had asked producers to limit sex scenes in the latest episodes.
Speaking on his Podcrushed podcast, Penn told co-host Nava Kavelin: "I asked [showrunner] Sera Gamble can I just do no more intimacy scenes."
The former Gossip Girl actor went on to say: "Fidelity in every relationship, including my marriage, is important to me.
"It's got to the point where I don't want to do that, so I said 'my desire would be zero, to go from 100 to zero'."
