The agents of the organisation that was hunting for XIII have finally captured him, along with his friends, but he's still refusing his captors' job offer. Forced to give in after they commit an appalling act just to coerce him, he's discreetly brought back to the USA, where he finally learns what they're really after. Meanwhile, Betty Barnowsky continues her own investigation under the FBI's very noses. For both of them, the road leads, once again, to Green Falls.