Two years after angry birds 2 the flock was enjoying a peaceful day when at scientist pigs lab hev was making a storm. Not just any storm but an infection storm. It would infect anything in it's path and make it evil so the pigs are immune. But not the birds. When the storm was created but the sharp eyed Red spotted it he yelled and ran along with the other main birds. They hid in bushes under rocks and in trees. Only red survived the infection.
same as angry birds 2 but no lives system and you can be pigs.
birds (suggest new ones in the comments):
1-1 red:no ability
1-3 chuck: super speed
1-8 bomb: explodes
1-15 blues (Jay,Jake,Jim): split into 3
1-17 Matilda: drops egg bomb
2-1 Terence: super strength