I'll be honest - we're throwing science at the wall here to see what sticks.
My game group played The Letter (introductory scenario) in London Dread for the first time last night and we were confused about turning cards over. We read that you can turn cards over BEFORE you program your movements, so we turned all the cards over then programmed the movement. To me that didn't seem right. Isn't the point to program your movements THEN turn the cards over? It wasn't really clear. Can someone explain how that works, please? If you programmed your movements before turning the cards over you'd have no idea if you were sending the appropriate people to handle the cards. You turn over as many cards as you want making sure to reveal all of the Plot cards and then work out how your group is going to handle the cards you've revealed.