Dessert is over. Then the razors come out.

Uriah Kiser sits down with the cast of Sweeney Todd: The Demon Barber of Fleet Street at Riverside Center for the Performing Arts, the Stafford County dinner theater at 95 Riverside Parkway in Fredericksburg. The Sondheim musical thriller runs Sept. 9 through Oct. 25. Christopher Sanders, playing Sweeney for the fourth time and in his fifth Riverside show, talks revenge, the “Epiphany” breakdown he now walks into the house to deliver, and the trapdoor that stays open for the entire second act. Elizabeth C. Butler (Beggar Woman / Lucy Barker), Madison Cox (Johanna), John Sheldon (Tobias Ragg), and Marco Giacona (Anthony Hope) break down the asylum sheet scene, the ensemble’s brutal score, and why Mrs. Lovett — played by Nancy Anderson — gets the laughs while pulling the strings.

Kiser had neve ...