George Gibson is determined to check off the last item on his bucket list: a trip across America. He hops in his RV to visit - and sketch - the buildings and places across America that he and his wife never got to see. When his daughter learns of a young boy forced to give up a beloved Saint Bernard named Lewis, she suggests George adopt the animal as a traveling companion. The dog even fits perfectly in the sidecar of George's Vespa motor scooter.
As George warms to his travel mate, he begins talking to Lewis, sharing stories from his life and his unrealized dreams. Along the way, Lewis seems to attract people and make instant friends with the quirky and charming, funny and odd people who cross their path.
Could it be that his new friends - and this strange dog - will help George to finally confront the secret he's been hiding? Can Lewis's devotion to the truth be enough to save George from himself?