Susan King is watching three men loading illegal arms into a truck. She prepares to shoot, wanting to leave one alive for interrogation, but she is shot at by a fourth man acting as lookout. She quickly shoots him, but the other three men are alerted to her presence. Two run towards her while the other jumps in the truck and takes off. She fires at the explosives in the truck. It explodes, but the two men are unhurt and continue to run towards her. She runs away and they give chase. She crosses a street, and one man stops to take aim at her. He is, however, hit by a bus. The other man runs off.
Charles Leyton is meeting with the Doctor. He is concerned that all of British journalism is controlled by one man: James Baron. Baron is using paranoia to promote isolationist propaganda. Leyton wants the Doctor to investigate Baron with the help of field agent Susan King, who knows Baron better than anyone else. After stopping briefly at Susan's hotel room, where the Doctor disarms a bomb meant for Susan, they head for Baron Enterprises.
They bluff their way in, and head for the computer terminals. Their credentials don't allow them to get very far, so they head for the top floor, Baron's offices. They find evidence that Baron is planning a coup, and was also behind the illegal arms deal Susan broke up earlier. She implies to the Doctor that she needs to use the "convenience", and leaves him. Soon, he is shot at by a directed charge weapon. He surrenders and is taken by two guards to Baron.
The Doctor and Baron talk but the Doctor is unable to dissuade him from his attempted coup. Just then, the Doctor sees Susan peering upside-down from the Floater in Baron's office. Baron regretfully decides he has to kill the Doctor. The Doctor throws his hat into Baron's face and runs for the Floater tube.
Meanwhile, Susan has sabotaged one of the Floater tubes, killing one of Baron's guards. Baron urges the other guard, Bob, to avenge his brother. More guards arrive.
The Doctor, chased by armed guards, escapes under the false floor and gradually and carefully makes his way towards the roof. On the way, however, he is grabbed by Bob, who shoves him against a window. As Bob pushes, the bottom of the polythene window breaks free, and he tries to push the Doctor through the gap. He makes a miscalculation, however, and falls through the gap himself. The Doctor takes the stairs to the roof.
On the roof, the Doctor blows up Baron's helicopter to attract the attention of the authorities. Baron appears, and is ready to kill the Doctor, but before he does, he informs the Doctor that, despite his money and power, the only time he was ever happy was when he was with Susan. He raises his gun, but is shot by Susan, who has climbed the radio mast.
As Baron dies, his last words are to Susan: "You came back."
- Baron Enterprises doesn't use PANs.
- The Doctor mentions Bessie.
- The Doctor blows up Baron's helicopter.
to be added
to be added