Kevin is proud to be able to present his award-winning "mind machine" to his schoolmates and teachers. But after a few confused sentences, he runs off the stage of the auditorium. Then his friend Nadine disappears. There's no time to lose--it's a case for TKKG! Tim, Klumpling, Karl and Gabby take advantage of an outing to undertake a daring search for the lost children. They sneak into the empty, dilapidated house of Kevin's parents, and what they discover there takes their breath away: a new prototype of the spectacular mind machine! The quartet begins to suspect that this could be the reason for the disappearances. But who's behind all this? And what role is Mr. Manek, the biology teacher, playing here? Is Kevin conspiring with him? Their investigations take TKKG deeper and deeper into the mystery of the mind machine and on the track of a sinister experiment. It's the beginning of an adventurous journey of discovery into a bizarre world of real and virtual surprises.