In Fairy Tail Edolas Arc, Gildarts makes it back to Fairy Tail after his 10 year long S Class mission. Everyone is rejoicing his arrival, including Cana Alberona, Elfman Strauss, Mirajane Strauss, Levy McGarden, Natsu Dragneel, Gray Fullbuster, Erza Scarlet and many more in the guild. During the fiesta, a sudden event makes every one disappear. The only ones left are Wendy Marvell, Carla, Natsu Dragneel, Happy, Gajeel Redfox, Mystogan, Lucy and her celestial spirt, Holigram. Wendy, Carla, Natsu, Happy and Lucy are able to meet up and agree to save their friends, who, along with the rest of Magnolia, disappeared. Gajeel departs later into Edolas while Mystogan looks for other survivers. Eventually, Earthland Gajeel and Edolas Gajeel work together to save the huge lacrima's from being cut open, they end up being just Earthland Erza and Gray. When Wendy and Natsu are being strapped down and stripped of their dragon power, Lucy, Happy, Gray, Carla, and Erza go to find and rescue their friends. Erza Knightwalker instead stops them and from there the battle begins. You can learn more at the Wiki.