Truman is small and sweet as a donut, thoughtful and calm like his Sara. You wouldn't consider him brave, but he would go anywhere with her.
One day something new happens: Sara takes a really large backpack, puts a blue bow in her hair and takes the noisiest bus, the one to think new thoughts.
Truman then decides to gather all his courage and undertake a rescue mission, provided he can overcome the terrible challenges that lie before him: the taller terrarium, the wider carpet, the scarier toys.