For more than two years, Alan and Kirsty have been developing a highly sophisticated robot which closely mimics both the physical and intellectual properties of human beings. After some false starts, they design and build two prototypes - Jack and Jill - and decide to test their credibility as human by visiting an old friend. The test is a success, and they also find that the learning potential of the mechanoids is much greater than even they understood. Meanwhile, the MoD is taking an interest in strengthening their military might with a platoon of mechanoids. The prototypes are put in charge of assembling and programming these combat units. However, Jack and Jill seem to be developing a more than robotic sensibility for the 'family' of mechanoids they are building... As senior members of government start to act strangely, and the robot platoon goes AWOL, Alan and Kirsty are left wondering whether their invention will prove to be a boon... or a dangerous threat to humanity. With the help of their old friends, Weasel, Knuckles and Kevin, they are going to have to track down the rogue mechs and make some hard decisions...
