``Watchmen`` is set in an alternate 1985 America in which costumed superheroes are part of the fabric of everyday society, and the ``Doomsday Clock`` - which charts the USA’s tension with the Soviet Union - is permanently set at five minutes to midnight. When one of his former colleagues is murdered, the washed up but no less determined masked vigilante Rorschach sets out to uncover a plot to kill and discredit all past and present superheroes. As he reconnects with his former crime-fighting legion - a ragtag group of retired superheroes, only one of whom has true powers - Rorschach glimpses a wide-ranging and disturbing conspiracy with links to their shared past and catastrophic consequences for the future. Their mission is to watch over humanity... but who is watching the Watchmen?``