Steed gets an invitation to take part at a dressing party on board of a small plane. When all the seven guests are in it appears everyone has got different invitations with another host. Besides, no one seems to know each other. But they find out they all have their specialism which discriminates them from each other. Later when the plane has landed on a small isle, their host, who is unseen, tells them there is a killer in their midst and everyone has to find out for themselves who it is. Indeed, a few guests will die. But then unexpected there is Emma to save the survivals.