12 year-old Sebastian has decided not to follow his father and Angelina to Canada, deciding to stay in the alps to watch over Belle who has now become the mother of three beautiful pups. When a stranger arrives claiming to be Belle’s rightful owner, Sebastian will do all it takes to protect his best friend and her little ones.

Christian, a visionary scientist, studies wild geese. For his son, a teenager obsessed with video games, the idea of spending a holiday with his father in the wilderness is a nightmare. However, father and son will get together around a crazy project: save a species endangered, thanks to the ultralight of Christian! Then begins an incredible and perilous journey ...