That line is from Interview with the Vampire / The Vampire Lestat story arc, and it refers to the scene where Daniel calls out the vampire’s mind-reading act as “theater,” not a real power.

Where it comes from

The line is associated with Daniel Molloy confronting the vampire’s performance and saying, in effect, that the “ancient vampire” act was staged and the mind-reading claim was just for show.

What it means

  • “Ancient vampire” points to the character’s long life and reputation.
  • “You could read any mind you want” is Daniel rejecting the idea as a manipulation tactic.
  • “It was just theater” means Daniel is accusing the vampire of using drama, intimidation, and image control rather than actual supernatural certainty.

Best match

Based on the available coverage, this is tied to the season-two finale-era Daniel/Armand material and the broader vampire-interview framing in the AMC adaptation. If you want, I can also pin down the exact episode and scene as closely as the available sources allow.