"Patrick and Beth knew they'd be facing a danger more fierce than a polar bear or a walrus, but they never thought their opponent wouldn't be large enough to see. After arriving in Alaska in the winter of 1925, they discover that a very small enemy--a disease called diphtheria--is sweeping through the town of Nome. Can Patrick help retrieve enough medicine for the children by riding along with Clearsky and his team of sled dogs? Meanwhile, Beth makes a new friend who wants to prove she can accomplish this mission using an airplane, and she's not taking no for an answer. But can Amelia safely fly a plane over frigid and stormy Alaska? Will the dogs be able to get the medicine back to Nome in time?"--