Herms finds one day, that his shell isn't fitting quite like it used to. His mom and dad suggest that it's time for him to pick out a new one. But Herms loves his old shell, he doesn't want something new. He's had it since he was a very young hermit crab and he and his best friend, Nick, even have their own "matching purple shell" club. Everyone tells Herms that this is an important change, a good change, but change is scary. What if he won't like it? What if he doesn't look like himself anymore? Herms thinks that if he can just stop growing he won't ever have to change. He stops eating but...