Just before Christmas, Sophie becomes upset when children at school tease her for believing in Santa. Felix takes matters into his own hands and writes to Santa for proof of Santa's existence. Before you know it, Felix receives an answer from Santa mailed from the North Pole. Sophie has her proof but the globetrotting Felix ventures off again, this time to become Santa's newest little helper.Children will delight in opening the envelopes and reading not only Santa's letter but also the funny letters from Felix, who explains the Christmas customs he observes around the world. There's even a fold-out picture that opens up, showing Felix and Santa carrying gifts across the globe. Aspiring young Santa's helpers will want to wear the special hat that is included. While Sophie awaits her best friend's return, she, along with her family and friends, celebrates the holidays and marvels over Felix's adventures.