After a pleasant day out to thr spa with her friend Rarity, Fluttershy, a meek, yellow pegasus pony, is stopped by a single green ring that shot from the sky. It told her that she had the ability to overcome great fear, before inducting her into the Green Lantern corps, intergalactic peacekeepers.
However, unbeknownst to Fluttershy, the ring was not meant to go to Equestria. On the planet Oa, in the exact centre of the universe, the guardians lament the loss of a Green Lantern ring as they cannot go to Equestria due to it's high concentration of magic.
Since first claiming the ring, Fluttershy has enlisted the aid of her friend Twilight Sparkle in attempting to find out its purpose.