In wild Canada stands a white castle: Snowfields. At the boarding school, the world's best riders are trained and injured horses' souls are healed.

Zoe's friend Isaac needs a new horse for riding lessons, because his grey apple mare Samantha is not up to the icy winter temperatures at Snowfields. Zoe joins him on his quest - and travels with him to New Zealand! There she meets Isaac's ex-girlfriend, who urgently needs help from the budding horse whisperers, because her horse is behaving strangely. Or is this just an excuse to win Isaac back?.