Here's what I was going to say last week. They give you a written intro to grand jury procedure (and then show a video with a judge reading it out loud to you). At one point the intention is to impress upon you that you, the individual juror, lack the powers of the jury as a whole; but that's not exactly what it says:
You must bear in mind that a Grand Jury exists only as an entity, [...]Well, I'm glad we cleared that up. But is it identical with its essence?