Original: As the movie opens, it is shown that Thunderbolt is not exactly bright, and very self-centered and rude to his side-kick, Lil 'Lightning, which eventually provokes the Corgi to revolt.
Simplified: As the movie opens, it is shown that Thunderbolt is not exactly bright, and very self-centered and rude to his side-kick, Lil 'Lightning, which eventually makes him want to get revenge.