The Doctor is continuing working on his pet project, Rodney, a robot who breaks down and so the only way to fix him is go to the planet of Trade World where the robot parts the Doctor needs are manufactured.
When they arrive on Trade World they discover that the planet is in run by the International Cybernetics company, all of which is the doing of Mr Paul Rankin, a professor who specialises in the rights of robotics and is perfecting on his newest experiment, and developing human upgrades, but when his experiment goes horribly wrong the Doctor steps in to help. Can he save humanity and shut down the Cyber Grid, or is disassemble mathematically impossible?
