Seeker of the Blue Keys

One month after returning from Tenrou Island, Lucy is given a box containing a special Celestial Spirit Key. A long-buried secret from her mother's past is unearthed and Lucy is thrown into a world she would never have dreamed of. With the fate of her new-found friends on her shoulders, Lucy embarks on a quest to save the Celestial World. (Takes place after the Tenrou Arc)