In a small house on the edge of town lives Arthur (Freddie Highmore), Arthur has protected his house from bulldozers and unwelcome guests, with help from his secret friends. Arthur’s garden is home to wonderful creatures and he will do everything he can to protect them.

Arthur visits the wonderous civilization in his garden and learns that the beautiful Princess Selenia (Selene Gomez) is in trouble. She sent a distress call to Arthur and soon Arthur must do all he can to protect the civilisation and Princess Selenia from the dreaded Emperor Maltazard (Lou Reed).