This is the twelth picture book about Frog, and his friends Duck, Hare, Rat and Pig, and certain to charm his legions of admirers with more of his naive antics.

Frog is miserable, and he cannot see why. Nobody has upset him, and nothing has gone wrong particularly, but he stills feel blue.

Then one of his stalwart friends makes him laugh, and suddenly he realises he's not sad anymore - and he still doesn't know why!