Warning: SPOILERS through Justice League

The White Lanterns - the guardians of Life itself - have returned in a big way in the latest issue of Justice League. Given that all life in the universe has been endangered by recent events on Earth, it is not surprising that The White Lanterns should show up to lend a hand. The form in which they manifested, however, was completely unexpected. The White Lanterns first appeared in the climax of Blackest Night, a DC Comics' event that saw the various groups that draw their powers from the emotional spectrum generated by all sentient life (such as the Green Lantern Corps) forced to unite against a common enemy - the super-powered zombies known as The Black Lanterns. Drawing off the power of Death and the dark lord Nekron, The Black Lanterns grew more powerful with every soul they slew.