T1, E20: XANA has taken control of the assembly line in the deserted factory. Hervé and Jeremy’s droids, which they have made for the school’s Robot Encounters Day, are fighting one another in the gymnasium. Meanwhile, another much more frightening robot created by XANA turns up at the school, creating panic and mayhem. Our heroes have no time to lose. While Odd and Jeremy rush to the laboratory, Yumi and Ulrich try to eliminate the robot which is hot on their tails. But things are not as easy as they seem: the Robot has destroyed the laboratory, which means that no one can get to Lyokô until it’s up and running again, and Aelita is in danger ! What’s more, thanks to its artificial intelligence and reinforced armour, XANA’s Robot seems indestructible. And Jeremy has to stay in the factory to fix the lab ! Out of sheer desperation, Yumi and Ulrich will have to join forces with the enemy : and ask Hervé to help them!