Frog doesn't know why he's sad, but one morning when he wakes up, he can't smile, and he wants to be alone. Rat tries his best to cheer him up by dancing about, walking on his hands, balancing a ball on his nose, and, finally, playing his violin - which makes Frog cry! Then, quite suddenly, Frog is himself again, laughing and pleased with life. Gentle and subtle, this story, like others about Frog and his friends, shows us ordinary, everyday emotions in simple, artless pictures that say at least as much as the text.