A newly married couple, in the process of starting a family, learn many of life's important lessons from their trouble-loving retriever, Marley. Packed with plenty of laughs to lighten the load, the film explores the highs and lows of marriage, maturity and confronting one's own mortality, as seen through the lens of family life with a dog.

Fall into puppy love with “the world’s worst dog”, who now has a frisky voice and an attitude to match. Join Marley for his mischievous puppy years, as he and his summer pal, Bodie Grogan, wreak havoc on a neighborhood dog contest. Marley outwits Dobermans, Shepherds and Collies, while stealing hearts in his own unique and lovable way.