Water Thief — Julia Golding

Meet George - the youngest Universal Companion - and his best friend, Malvin, the rudest goblin on Earth.

The world is spinning into environmental disaster and the Society for the Protection of Mythical Creatures has shaken off years of inaction and swung into action to defend it. George has just been put in charge of his first mission and sent to the island paradise of Zanzibar to hunt for disappearing water sprites. But how is he going to succeed with a changeable weather giant, a single-minded cyclops, a haughty phoenix, not to mention a certain grumpy goblin on his team?

Yet George is to learn that the biggest enemy is the one you can't see until it is too late.