The Rocky Horror Picture Show - UK (1975), directed by
Jim Sharman from the play by Richard O'Brien.
A couple (Susan Sarandon and Barry Bostwick), whose car breaks down on a dark and stormy night, take refuge in an old dark mansion where a mad transvestite scientist, Doctor Frank-N-Furter (Tim Curry), is trying to make the perfect man.
Conventions are an opportunity for Rocky Horror fans from far flung places to gather together. Common convention elements include costume contests, vendor tables, fan club president Sal Piro, pre-show skits performed by various casts, shadowcasts of related movies (e.g. Shock Treatment, Clue, Hedwig And The Angry Inch), and of course a screening of The Rocky Horror Picture Show with an all-star shadowcast.