Price, a former hitman, is struggling to cope with retirement. He left the assassination business to live the "easy life." However, retirement arrived with its own agenda. It was not the instant peace and calm that Price expected. Rather, it was emptiness, boredom, and, worst of all, restlessness. The Last Lullaby plummets Price back into his old life and forces him into a corner from which he may never escape. Price's old ways no longer work for him when his heart opens, and he finds life beyond his profession. The tension finally boils, as Price must decide to close himself off again or open himself up to a world beyond his control.
We don't really know what happens to the dog. He runs off, the owner cries and says he'll come back, then the writer appears to have an attack of amnesia and forgets the dog was ever part of the script.