'Lottie, Hamish and Whistle all agree that school crossing road safety rules are important.
'Luckily, Hamish is fluent in the language of Whistle and spends much of his time trying to teach his friends. Lottie the lollipop lady and Whistle himself join Hamish in teaching 'Whistle' to crossing users.
'Soon everyone discovers that the language of safety is necessary and a lot of fun to learn.'
Source: Back cover blurb.