Cult musical The Rocky Horror Show is returning to the theatre where it was first staged 33 years ago for a one-off performance tonight.
The production at London's Royal Court Theatre will feature original cast members as well as star guests.
They have all waived their performance fees for the show, which is in aid of Amnesty International UK.
Organisers expect the 396-seat theatre will be sold out for the two-hour extravaganza at 7.30pm, with fans paying between £50 and £350 for tickets.
It revives the play as first performed in 1973. Creator Richard O'Brien has rewritten a number of the original characters' roles.
The musical ran for a few weeks at the Royal Court before moving to a new venue and it has been touring ever since.
It was adapted for cinema as The Rocky Horror Picture Show in 1975 and the theatrical version was later adapted in line with the film version.
Performances of the camp musical are usually enlivened by the audience participation of outrageously-dressed fans.
Guests appearing in tonight's production include O'Brien, Ade Edmonson, Anthony Head, Toyah Wilcox, Nell Campbell, Ben Richards and Patricia Quinn.
The show is to be narrated by Jamie Theakston and Steve Pemberton from The League of Gentlemen.
O'Brien said: "There couldn't be a better cause for Rocky Horror to support than Amnesty, which continues to defend free expression and stand up for people's rights all over the world."
