One day, a shaggy dog (its name is Secret) arrives at Spence Mansion, which is the house of Seymour, Mr Grumpy and Olive. Secret is a dog of Noah Breth, a dead man whose children are fighting because of Noah's money. Seymour wants Secret as his own dog, but Olive and Mr Grumpy disagree about it because Secret begins barking all night long. Why Secret barks like this? It isn't the only reason that he misses his old master...