An elephant named Gerald and a pig named Piggie are best, best, "bestus" (a word Gerald and Piggie made up that means "very best") friends, but Gerald worries that something could go wrong that would end their friendship. Piggie is not worried at all. She's even happier and more excited than usual. That's because she and Gerald are invited to a party hosted by the Squirrelles, three singing squirrels who love to have a good time. And so begins a day when anything is possible.