Every performer the series billed in its cast list across its six seasons, from 2007 to 2012 on The CW. That is the whole rule, and it takes in ten actors, from the top of the cast list to the bottom of it. The large recurring and guest company is out, however well you remember them, however many episodes they turned up in. The voice that narrates the show is out too: that performer was never credited on screen and never appears in the cast list, so the narration is a fact this set can tell you about rather than an answer you can type. The answer is always the actor, never the character. A surname on its own counts. Nothing in this set gives away the story: no question, clue, option or answer tells you who is behind the blog, and nothing anywhere tells you which seasons a performer was in.