rtemis Fowl is back.

The Opal Deception, the fourth book in Eoin Colfer's popular children's series, has just been published.

And if you are not familiar with the exploits of Colfer's mercenary teenage 'hero', this is a good time to start.

Here's a primer on the first three books.

Artemis Fowl: Book 1

The first book, published in 2002, introduced readers around the world to then 12-year old Artemis: a millionaire, a not particularly modest genius. And a criminal mastermind with grand plans to steal gold from the Fairy People livng underground.

The Fowl character subverts popular notions of what the hero of a children's book should be; but the fairy people themselves are scarcely what you would expect from Enid Blyton-esque tales.

They are tech-savvy and dangerous when people try to mess with them -- which makes the mindgames between Artemis and his opponents (especially the ass-kicking Captain Holly Short and her senior officer Commander Root) so interesting.

Thrown into the mix are a destructive troll, a tunnel-digging dwarf, a centaur named Foaly and even a few observations about what human beings are doing to their planet. Great, irreverent entertainment.

Artemis Fowl: The Arctic Incident (Book 2)

A slightly older, perhaps even mellower, Artemis discovers his father -- who was presumed dead - is being held to ransom, and he diverts his resources to helping him.

But sparks fly between him and his old nemesis Holly Short when she suspects Artemis has been supplying illegal power to the evil goblins.

The James Bond-style storyline with the inevitable doses of black humour make for a fine entry in the series.

Artemis Fowl: The Eternity Code (Book 3)

Slightly less well received than its predecessors, but a bestseller nonetheless.

The third book in the series has Artemis facing off against human enemies, which takes some of the charm off the story.

Also, the protagonist, originally meant to be an anti-hero, is getting increasingly likable as his enemies become more villainous.

Still, there's just enough of Captain Short and the dwarf Mulch Diggums to salvage this
entry.