How is Artemis fowl tricked by the LEP when his plan begins to crumble?

In Chapter 7, we see the narrative building towards the climax of Artemis Fowl. For the first time, the fairies have outsmarted Artemis by feeding a video loop through his security cameras. When he discovers this, he is shocked: "Artemis glanced at the landing cameras. Deserted. From every angle. Definitely no waving manservant. He studied the monitors, counting under his breath . . . There! Every ten seconds, a slight jump. On every screen . . . Artemis's stomach dropped into a queasy hell. Duped! He, Artemis Fowl, had been duped, even though he'd known it was coming. Inconceivable" (179).

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