Book excerpt: The bitter cold and three months a year without sunlight make Antarctica virtually uninhabitable for humans. Yet a world of extraordinary wildlife persists in these harsh conditions, including leopard seals, giant squid, 50-foot algae, sea spiders, coral, multicolored sea stars, and giant predatory worms. Now, as temperatures rise, this fragile ecosystem is under attack. In this closely observed account, one of the world's foremost experts on Antarctica gives us a highly original and distinctive look at a world that we're losing.