Johnny is the eager-to-please ASM and understudy to arrogant actor Roger Kite, who is due to play Andy Warhol in an upcoming West End production. Roger treats Johnny abominably, forcing him to make his coffee, sort his fan mail and - particularly - keep him away from the theatre's lucky mascot, a black cat called Diddly. As opening night approaches, Kite's attitude worsens, causing the young man to hear voices urging him to prevent Kite from starring.