When you sign-up you receive a top-secret file containing your target's information. To "kill" your target, you must follow the pattern to make a weapon (a pair of socks) for your event, and mail it to your target. Your target is "dead" when they receive your weapon. Your target then sends their incomplete weapon to you, along with their target's information, and you complete their weapon to kill their target. At the same time you are trying to kill your target, your assassin is trying to kill you.