Wolfie trains Oso to pilot a submarine. Unfortunately, Oso leaves the hatch open, and Wolfie's submarine fills with water and sinks. That's when a special alert comes in. A girl, Lena, accidentally breaks her grandma's flower vase while taking her dog Bo outside. Lena let Bo take the blame, and she feels bad for not telling Grandma what really happened. Will Oso show Lena how to tell the truth about the broken vase to her grandma?