Marley spots two motherless kittens by the side of the road and his family gladly adopts them, but as he tries to copy the cute behavior of the little felines, the large puppy causes more and more trouble.

John and Jen are journalists who are a newly married couple. Marley is the adopted puppy that no one wants, a high-strung lab who is virtually untrainable. Marley shreds cushions, destroys floors and walls and most everything in between. Instead of taking him to the pound, they love their dog and he faithfully loves them in return. John and Jen eventually have three children and Jen gives up her career to be a mom. John's career continues to advance...