She knows, realized Artemis, but what Holly knew, he could not say exactly. She knows that something is different, that the even numbers have turned against me. Two twos are four fairies spitting bad luck on my plans.

Then Artemis reviewed this last sentence, and for a second its lunacy was clear to him and he felt a fat coiled snake of panic heavy in his stomach.

Could I have a brain tumor? he wondered. That would explain the obsessions, the hallucinations, and the paranoia. Or is it simply obsessive-compulsive disorder? The great Artemis Fowl felled by a common ailment.

Artemis spared a moment to try an old hypnotherapist’s trick.

Picture yourself in a good place. Somewhere you were happy and safe.

Happy and safe? It had been a while.

Artemis allowed his mind to fly, and he found himself sitting on a small stool in his grandfather’s workshop. His grandfather looked a little sneakier than Artemis remembered, and he winked at his five-year-old grandson and said, Do you know how many legs are on that stool, Arty? Three. Only three, and that’s not a good number for you. Not at all. Three is nearly as bad as four, and we all know what four sounds like in Chinese, don’t we?

Artemis shuddered. This sickness was even corrupting his memories. He pressed the forefinger and thumb of his left hand together until the pads turned white. A trigger he’d taught himself to elicit calm when the number panic grew too strong. But the trigger was working less and less recently, or in this case not at all.

I am losing my composure, he thought with quiet desperation. This disease is winning.

Foaly cleared his throat, puncturing Artemis’s dream bubble. “Hello? Mud Boy? Important people waiting, get a move on.”