Lots of snowblind courage in this one as Hank Sayers (fifteen? you can hope) and his four and six year younger siblings and his best friend Pierre go to meet Hank's parents at the family chalet up in the icy, isolated reaches of Switzerland. Whilst mother and father are stuck in the Simplon tunnel, the youngsters walk stoutly ahead up to the chalet, manage nicely, even take in the very little grandchildren of their only neighbor, old Monsieur Vanel, whose daughter is ill. It's la grippe which they diagnose as appendicitis, and, alone on his father's snowshoes. Hank goes down the mountain for help. The suspense entails a suspension of disbelief these children are all apparently as nerveless as they are self-reliant and likable, and the story coasts right along from one emergency to another.