This installment of the PBS series chronicles the efforts of a pair of snowy owls to raise their young during the 82-day summer season in the Arctic. While the mother protects the nest, the father hunts lemmings to feed his family. But this year the rodents are not as plentiful as others, forcing the father to travel farther afield than usual. As a result, the owls move their nest closer to the food source, an odyssey that takes them across a river -- and because the owlets have yet to learn to fly, they have no choice but to swim.