Thomas the mouse over hears poachers plotting to kill a pride of lions. The poachers' loyal dog then hears the mouse promise to stop them. The dog being loyal to his masters will not let some mouse ruin their plans. It's a race against time to move the lions before the poachers arrive, but who will the lions believe? A confident loyal dog or a timid mouse that can be eaten in a single bite. Will Thomas make it there in time? What can Thomas say to get a pride of lions to leave their home? Will the lions eat Thomas for his trouble? Will Thomas be able to keep his promise?