Michael C Hall has revealed that the unveiling of Dexter Morgan's secret has "invigorated" the show.
Blood expert by day and serial killer by night, his secret double life remained just that, until the finale of Dexter's sixth series, when his adopted sister Debra walked in on him as he plunged a knife into his victim's heart.
"I think Deb finding out her brother's secret changes the landscape of the show in such a fundamental way," explained the actor, who portrays the murderer with values.
"It's really been invigorating, in the seventh season of the show, to feel such a sense of vitality and newness on set, and that is testament to the way the writers have handled this revelation that has been hanging in the wings for some time. It's great."
Michael, who has won Golden Globe and Screen Actors Guild awards for his performance as Dexter, is remaining tight-lipped about what the consequences are in coming episodes, but teased: "I think it has a ripple effect that leaves nothing untouched. Every relationship, every dynamic in the show is fundamentally changed because of this."
The 42-year-old admitted that he and co-star Jennifer Carpenter, who plays his screen sister Debra, had an idea of what was to come in the upcoming storyline.
"Everyone on the show, definitely Jennifer and myself, have anticipated this development happening and I think the way they did it was really great," he said.
He added: "The first scene we shot for the seventh season was the scene in the church when she walks in, picking up immediately after the end of the sixth season. We were off and running - it was really fun."
:: Dexter continues on Fox on Sunday nights.