"Iron Maiden" singer Bruce Dickinson has penned the screenplay and will cameo in "Chemical Wedding", a biopic about occult legend Aleister Crowley.

Veteran actor Simon Callow plays a Cambridge university professor who becomes possessed by the infamous mystic's soul. Crowley claimed to be the devil and was notorious as the "wickedest man in the world" before his death in 1947.

Dickinson is convinced that Iron Maiden fans will enjoy the movie, telling Digital Spy that: "On several levels, I think it will be nice for them to see somebody from Maiden doing something else that gets the band's name out there and also potentially gets a bit of respect for heavy metal and all the rest of it. But, in addition, I think they'll just enjoy it. It's a rollicking good story."

A Fall 2008 release date is scheduled.