Mystery Halloween Party: This party idea is not for the casual host and requires a great deal of planning and coordination but is a lot of fun!  3-4 weeks prior to your party date send a mystery invitation to your guest list informing them they are being invited to a Halloween bash (I would suggest a costume party as it adds even more to the mystery) giving them the date and time only as well as adult or family party and informing them they will hear again from you soon. I have used a short rhyming message signed only as "your mystery host".  For your second letter give your guests a teaser on any fun events planned for the party and the menu (at this time letting them know if they should or should not consider bringing their favorite treat). Remind them of the date & time again and let them know they will receive directions in the mail one week before the event.  For your final letter you will need to set up a mystery path to your party location. This can be simple or complex depending on how much time you want to spend. Regardless though,   your final letter should still keep things a mystery.  For example: I gave directions to a local gas station with instructions to purchase a candy bar and say to the attendant "gee I love Halloween, this has been my favorite candy bar since I was a kid" I used a local gas station where I asked the attendant if he could respond by handing them an envelope with their next instructions (worth noting that I had no problems here but you will want to make sure you have a reputable attendant or you could end up with unwanted guests! The possibilities though are endless-use your imagination and customize it to your group of guests)  At this point you can either take them to another location or directly to your party location. Note here that if the party location is not your home address you can further work the mystery especially with the costume! These parties are a blast and although they work best when around the mysterious season of Halloween they can be used at any time.  If you are asking how you get guests to go to a party they know so little about...make sure that everyone knows someone else at the party, people will talk about their mystery letter (you of course can play along). My guests all enjoyed their Halloween mystery party which is still talked about 3 years later! Have fun!