Book excerpt: If you haven't met a Moomin yet, you're missing the most magical fun . . . It's winter in Moominvalley and the Moomin family are deep in their Long Winter Sleep, waiting for the sound of Too-Ticky's barrel organ to rouse them, as it did every spring. But when a mysterious ratta-tattle wakes Moomintroll with a start, will he be brave enough to investigate the noise on his own? And what surprises will he find if he does venture outside?