I'll agree with those up thread saying, if you're going to do this intro, do it as as a pre-campaign handout and a "theme" versus a first adventure.
One thing not mentioned yet: A good DM must have the trust of his players. Since this is your first time at the helm, you don't have it yet (even if these guys know you). Doing a first session where the players (and it is the players not just the characters here) are lied to and manipulated will likely fail to establish this trust and cause irreparable harm to this campaign and possibly future ones.
Think of it this way - do you really want the players double and triple thinking everything you tell them from this point forward (assuming this is not a conspiracy based game of course)? When you look at them and say "guys, this is pretty straight forward" - do you really want them to say "yeah, that's what you said the first session, and look where that got us!"
Edit: I will add there is absolutely nothing wrong with a "things are not as they seem" adventure, they can be great fun. But until the DM has the trust of his players they tend to go very badly.