The kids are asked to watch their neighbour's pet hamster and are given strict instructions not to let it out of its cage. However, Mouse doesn't believe any animal should live in a cage.

With the rest of the gang sick, Mouse builds himself his own bubble to avoid contacting germs but the rest of the family wants one too that it eventually leads to them getting one and considering using it as part of their everyday route that they don't want to leave their bubbles ever to avoid getting sick again.