Princess Luna has been keeping an secret from every pony, even her sister. Trixie was not the first Pony to join the Sinestro's Corps. She was! The ring came to her during Nightmare Night, long before Twilight join the Green Lantern Corps. After hearing about Trixie being an member of the same corps, Luna takes her power ring and sent out to show that no all ponies will use fear to get what they want. However, she first has to convicts everypony that she not like Trixie, even her sister. Will Luna show that she can use fear to help or will it be like Nightmare Moon all over again?

"In blackest night, in brightest day, no evil force shall have it's way. Let all dark forces within my sight, learn to fear the yellow light."

An side story to Green Lantern's Light.