The story of the friendship of the brave orphan boy Sebastian and the smartest white dog Belle. Having survived the Second World War and many trials, they happily healed in the French Alps, along with a foster family and three puppies. Friends are separated by a cruel man named Joseph, who declares himself the real owner of Belle. When he kidnaps dogs, Sebastian sets off in pursuit of snow-capped mountains.

12歲法國男孩賽巴斯蒂安從小沒有母親，陪伴他長大的是爺爺與心愛的大白狗貝兒。這一年，貝兒生了3個孩子，家裡變得熱鬧不已。某日，一位不速之客登門拜訪，他宣稱自己是貝兒的主人，揚言要把貝兒與狗寶寶帶走。賽巴斯蒂安要用盡方法保護貝兒一家人，絕不輕言放棄。