Red, Chuck and Bomb climb the mountain on their island and find the Giant Eagle, but he's now overweight and disinterested from helping out his little feathered friends.
The pigs trick the birds by holding a huge party, then making off with the eggs while they are too busy enjoying themselves. Only Red saw through the act, and when the birds find all the eggs gone, the Judge turns to Red for help.
Red inspires the others, and they build a makeshift raft and follow the pigs across the ocean to Piggy Island.
Meanwhile King Pig is a hero to his people, and they prepare the eggs for a huge feast.
The birds approach the pig's city, and prepare the giant catapult. Matilda is launched first, and can fire magic egg bombs, but it doesn't cause enough damage. More birds are fired over, until Red asks Terence to pull back the catapult further and he makes it into the main castle.
Chuck and Bomb also make it over, but Terence accidentally breaks the catapult so the little birds are on their own. King Pig sends his army to hunt down the birds, and the Mighty Giant Eagle is back on the scene and flies in to help out.
King Pig hides the eggs in a vault, but the birds are too late and they are en route to the kitchen. The birds manage to distract the pigs, and Giant Eagle carries them all away except one. Red and King Pig fight and fall to the castle dungeons, amongst barrels of dynamite, before the final showdown.
King Pig lights the fuse, but Red manages to grab the last egg and hides under the giant pot that was going to cook the eggs, while the barrels explode, bringing an end to Pig Island.
The birds are at a safe distance, where some of the eggs hatch and they are reunited with their parents. The celebrations are back on when Red emerges from the wreckage alive.
Later, back on Bird Island, life is back to normal but they are a happier community, and Red's house has been rebuilt in the center of town next to his new pals ... although he needs to share it with Chuck and Bomb!