More than 15 million viewers are expected to watch Friday night's episode of EastEnders.
In celebration of the soap's 25th anniversary, the programme will be shown live, and will reveal the culprit behind Archie Mitchell's Christmas Day murder.
To ensure full secrecy, EastEnders bosses have ordered ten different endings with ten different murderers.
Only six people know the identity of the killer, and the chosen murderer will find out just ten minutes before the end of the show.
Photo: ę BBC