Bannister家来了一只新宠物，Zeus原先是警察特种部队的一只英雄犬，然而在Bannister一家看来，做一只牢靠的看门狗它似乎并不够格。圣诞节前夜，Bannister一家出门后，两名夜盗闯进了屋子。Zeus大显身手的时候来了...

    The Bannister family's new addition, Zeus (voiced by Mario Lopez), a former K-9 police hero, appears to be less than the dependable guard dog the family needs. However, when two burglars (led by Dean Cain) set out to break into the Bannister's home while they're away for Christmas Eve, Zeus seizes the chance to be a hero, proving every dog - even this one - has his day.