I don't want to go into the plot of this excellent Anime production, as I really enjoyed seeing the story unravel, and I don't want to take that away from you, if you decide to buy it. Suffice it to say that the confusion you may experience in the first 5 minutes is nothing to worry about - everything is explained in the end.
It would be really easy to be cynical about this film. Post-apocalyptic setting? Check. Teenage, slightly gauche, male hero? Check. Tom-boy female minor character, in love with the hero (who hasn't noticed)? Check. Massive vehicles, including an armoured train? Check. And you could argue that, at its heart, is a very simple parable about working with nature rather than against her.
But this all becomes irrelevant, as the enchanting story-line and the truly jaw-dropping visuals sweep you along. In just over 90 minutes they tell a wonderful self-contained story, that will still manage to feel fresh to all but the most jaded palates. Scarcely a moment is wasted, everything serves to move the plot forward, and you are never more than a few minutes away from an image that will take your breath away.
If you first came to Anime via 'Spirited Away', and want to know what to watch next, this would be an excellent choice.