During an airborne test of an experimental airplane fuel flow controller, something goes wrong and the plane crashes, killing the test pilot. The forth failure in a row leads to public hounding of the project's leader, Scott, and he plans to abandon it. However, his old friend Peter Brady suspects that there might be sabotage to blame...

A young woman named Ellen Summer escapes from a private asylum and runs into Brady on a train, begging him to help her, she claims to have evidence that could save an innocent man who is sentenced to hang for a murder he did not commit. Skeptical at first, Brady decides to meet with the man himself, and when they both tell the same story, he decides to investigate further...

After some important scientific research is stolen, Brady is sent to Amsterdam to identify it after its recovery, but when the British agent is captured by local police, Brady himself has to find the papers and save the agent from jail.

When an outspoken Russian writer is detained at the country's frontier while on the way to a major awards ceremony, Brady decides to cross the border himself and let her out, but he quickly runs afoul of the local military commander...

When a scientist at Brady's lab suddenly burns all of his papers and runs away, Brady sets out to investigate and discovers that he wasn't entirely acting of his own accord.

Toni Trent, one half of a pair of twins and a popular double-act, performing for the troops on a USO tour of Britain finds herself in trouble when she witnesses a killing, and is kidnapped. When her sister Terry arrives in the country and finds Toni gone, she looks to Peter Brady to help.

A UN inspection fails to find the suppliers selling weapons to terrorists operating in the Middle East, however the British representitive Zena Flemming suspects that she might be able to find more evidence if she heads back alone, but takes Peter Brady with her for protection, and as a second pair of eyes.

A young woman walking through a park in France discovers a rabbit that materialises in front of her. Taking it to the government in Paris, they are concerned that it could represent unofficial scientific research and call in Peter Brady from London to take a look at the creature and discover if it could really have been invisible. Heading down to where the creature was found, he discovers a sinister project...

In a small Middle Eastern country, the head of the army presents a plan to the King to exploit their position as friends of the major Eastern and Western powers to blackmail major governments. The King refuses to sign and is shot dead, his younger brother, Prince Jonetta is attending a science lecture at his University in Oxford when he learns the news. Brady was presenting the lecture, and decides to sneak aboard as Jonetta travels back home, suspecting there might be trouble...

After loosing big at gambling, Smith, the transport officer at Castle Hill is offered a large amount of money to leak the departure time of a major new experimental rocket section that is being driven up to Scotland for testing. The shipment is hijacked, and Peter Brady who worked on it, sets out to track it down.

Military scientists have been working on a new form of explosive mine containing a light sensitive cell (designed by Peter Brady), that will detonate when a shadow passes over it. During testing there is an accident and an officer is trapped in a pit next to the mine, unable to move. With only a few minutes before the edge of the pit casts a shadow over the sensor, they call the only man in the world who could get to the mine without casting a shadow...

After a plane crashes on arrival at a British airport leaving no survivors, the investigators discover that a component for an atomic bomb had been hidden inside some of the baggage. They suspect that individuals might be planning to plant a bomb under London and begin the search for a replacement piece that would probably be on its way.