Knock! Knock! Choo! Choo! Vroom! Vroom! As Russell awaits a visit from his brother, with every sound he wonders: Is Angus here? No, not yet. But with his ears – and his heart – wide open, Russell responds to the calls of a series of strangers who become his friends. Good thing because – Ting-a-ling! Ting-a-ling! Did you hear that? It sounds like Angus needs to be rescued!