The Four Horsemen was originally written by Dave Mustaine in his former band "Panic" entitled "The Mechanix". The song was one of Metallica's staples during their clubbing days, albeit with no melodic interlude and different lyrics. The original lyrics were roughly about a sexual encounter at a gas station. James Hetfield has gone on to say the lyrics were "silly". The original song The Mechanix was later released with its original lyrics on Megadeth's debut album Killing Is My Business... and Business is Good! as "Mechanix", with a new intro and a much, much faster tempo.