The Arctic sun sets and won't return until Spring. Winter has begun and with less solar energy the northern hemisphere freezes, life is at its hardest.
By June, the top of the planet is in 24-hour sun, while the south is frozen in darkness, but things aren't as simple as hot and cold. This is a season of feast and famine, fire and torrential rain.
As the Earth comes to the end of its journey around the Sun, for those animals that succeed, their place in next year's circle of life is safe. Fail now and fail the next generation.
In the time it takes us to complete our annual orbit around the sun, a newly hatched penguin chick grows a fluffy coat. Red squirrels battle for food, and an elephant family weakened by drought suffer a terrible loss.
By the help of scientists, conservationists and community members, the crew uncover new behavior, use pioneering and inventive techniques and even put their lives on the line to protect the animals who share our fragile home.
