Animation. Dennis lives in Beanotown with Mum, Dad, little sister Bea and his pet dog Gnasher. Gnasher is more than a dog to Dennis; he is a kindred spirit. Whatever Dennis does, Gnasher does with him.
Together with their friends Curly and Pie Face, Dennis and Gnasher believe that the world truly is their oyster and that kids should make the rules. Not everyone agrees, including Mum and Dad. But Dennis and Gnasher are not going to let that stand in the way of their pursuit of fun!
When he realises that Gnipper is imprisoned in Beanotown dog pound, Dennis sets up a dramatic plan to rescue him. Gnasher must enter the dog pound under false pretences and help Gnipper break out. However, when Gnasher does not come home with Gnipper, Dennis takes it upon himself to rescue them both. Posing as a misbehaving dog, Dennis is seized and sent to the dog pound.
On his arrival, he realises exactly why Gnipper and Gnasher have not come home - the dog pound is a dog palace! There is a pool, beauty treatments, lots of food whenever they want, couches and beds. In a room full of pampered mutts, Dennis finally spots Gnasher and Gnipper reclining by the poolside. Gnasher is ecstatic to be reunited with his best mate, as is Dennis, but trouble arises when the kennel warden arrives. She loves Gnasher and does not want to see him taken away. Despite the sausages on offer, Gnasher makes his choice clear and, together, the three of them escape from the kennel to go home.