When it is not known if aliens headed to Earth are friend or foe, five people are placed in secret bunkers to switches that, if not pressed at specified intervals, will set off mass destruction that will destroy everything, alien or human alike.When it is not known if aliens headed to Earth are friend or foe, five people are placed in secret bunkers to switches that, if not pressed at specified intervals, will set off mass destruction that will destroy everything, alien or human alike.