In a universe as vast as it is mysterious, an elite, powerful force has existed for centuries. Protectors of peace and justice, they are called the Green Lantern Corps. When a new enemy called Parallax threatens to destroy the balance of power in the Universe, their fate and the fate of Earth lie in the hands of their newest recruit, the first human ever selected: Hal Jordan (Ryan Reynolds). Hal is a gifted and cocky test pilot, but the Green Lanterns have little respect for humans, who have never harnessed the infinite powers of the ring before. But Hal's humanity is one weapon no member of the Corps has ever had, and if - with willpower, determination and the encouragement of fellow pilot and childhood sweetheart Carol Ferris (Blake Lively) - Hal can quickly master his new powers and find the courage to overcome his fears, he will save the Earth and all of mankind from certain destruction.