Death on the Web

Five people receive a message on a new social website inviting them to a reunion for a weekend to a house in Dorset. They all knew each other from school but not all of them became friends. It is now 20 years later so why would anyone want to bring them back together? All of them accept the invitation and travel towards their destination of doom. What will be install for them? Will it be a gruesome death or an experience that will haunt them forever?