The film's emotional climax hinges on a massive, tear-jerking twist for the character of Ethan, but not the audience. After reincarnating as a St. Bernard-Australian Shepherd mix named Waffles, the dog is neglected by his owners and eventually abandoned. Wandering through the countryside, his keen sense of smell picks up a familiar scent, leading him back to Ethan's old farm.
He finds Ethan, now an old, bitter, and lonely man. Renamed 'Buddy', the dog orchestrates a reunion between Ethan and his estranged teenage sweetheart, Hannah, leading to their marriage. However, Ethan still does not realize Buddy is Bailey. To prove it, Buddy digs out an old, deflated football from the shed and prompts Ethan to run a very specific play. When Buddy leaps off Ethan's back to catch the ball in mid-air—a trick they invented decades ago—Ethan freezes. Buddy responds to the secret phrase 'Boss Dog', confirming the impossible: his childhood best friend has returned in a new body. The film ends with Ethan retrieving Bailey's original collar, fully validating the dog's life-spanning journey.