Kayo is riding aboard Fireflash, a supersonic airliner invented by Brains, but she is unaware that its controls have been tampered with. International Rescue notices the plane has vanished from their monitors and attempt to locate it. Kayo realises that the plane is flying in the wrong direction, and manages to avoid a powerful gas attack that has knocked out both passengers and crew.

A strange malfunction occurs on a high-speed train in Japan, leaving it out of control and unable to stop. Brains comes up with a plan to fix the problem before a disastrous crash occurs - the only problem is that he will have to board the speeding engine himself to pull it off. Scott manages to get the genius on board, where they find the problem is more complicated than they thought.