Doomwatch's Anne Tarrant and Spencer Quist are placed on a government committee investigating whether the UK's censorship laws should be revised. The committee's work brings them into contact with both anti-pornography pressure groups and a man who hopes to one day be a dictator.

What if a man-made virus with the power to melt all plastic became as infectious as the common cold? When a plane crashes in South America, in quite extraordinary circumstances, it's up to Dr Quist's team to avert further disaster.

Doctor Quist and Doomwatch become embroiled in an inquiry into the heart-transplanting practices of Doctor Patrick. Several uncomfortable questions are raised: what has he been doing to a newborn baby that has been placed in his care, and should genetic engineering be permitted in society?

When a lifeboat crew discovers a luxury cruiser adrift in the English Channel, they find on board are a group of wealthy pop stars and their girlfriends, one of whom is dead. Doomwatch investigate, and discover that the death was not from drug abuse as was previously suspected; instead they begin to uncover the facts behind the dumping of a deadly chemical warfare compound in a deep sea trench, which seems to be far from dormant.

Doomwatch are joined by Doctor Robson, sent to undertake tests on the new 'Sahara' spray which is apparently capable of destroying all plant-life on the planet. But when Quist receives a phone call from the ministry, he is given orders to immediately suspend both Robson and Toby without any explanation. Closer investigation leads Quist and his team to discover that a new computerised security system run by Commander Keeping and Barker has become far too powerful, and is making its own decisions about government personnel.

Dr Quist attempts to go on holiday, but gets involved instead in a series of jet engine experiments causing harm and the same mysterious hallucination.

In an effort to prevent unofficial strikes by its workforce, a company in the North of England decides to use the latest scientific discovery, and attempts to manipulate both the working and the private lives of its employees by bugging them with listening devices. However, when Quist hears of this underhanded practice he is furious and decides that the only way to stop the unethical management is to turn their own method against them.

A military plane ditches into the sea whilst carrying three nuclear weapons on board. While the RAF mounts a search mission, an unidentified object is washed up on the shore near Byfield pier on the south coast of England. It is found by two men, Geoff Harker and Sam Billings, who decide that it must be a weather detecting device, and so begin to strip it down for parts. Toby is sent to investigate the device, but he soon finds himself faced with the terrifying prospect of disarming a very live bomb.

The Doomwatch team investigate the mysterious outbreak of a deadly subtropical disease which somehow has cropped up on an isolated island off the coast of the UK.

An inquiry into Doomwatch is begun following the events surrounding Ridge's breakdown. Meanwhile, Quist is summoned to a large country estate in Scotland, where he finds himself offered a new position with both power and wealth in the private sector, but only if he will curtail his investigations into a new drug called disocyanate. Back in London, the Minister decides that it is time to place his own man within Doomwatch, and so despatches Commander Neil Stafford to join the team.

Many years ago, Quist worked on the infamous Manhattan Project, which was instrumental in the designing of the atomic bomb codenamed Fat Man, used to obliterate the seaside port of Nagasaki in World War II. This involvement has continued to weigh heavily on Quist's conscience ever since. Hearing the phrase "Say knife," he recognises a potential threat - one that is tied into a break in at a plutonium base. A group of young student activists has stolen several radioactive fuel rods, and are planning to construct their very own atomic device.

A vicar collapses during a sermon, and there are seemingly unrelated events, one involving John Ridge. The answers are out there, but are obscured by big business and profit margins.

A revolutionary new lipstick goes on sale, containing pheromones designed to act as an aphrodisiac in order to make the wearer more attractive and desirable to men. This prompts Quist and Bradley to begin an investigation into the effects that pheromones have on people, and how they can alter the illusion of free will.

Ridge continues his ecological crusade by warning against the dangerous side effects of the chemical insecticide known as D.D.T. upon the world's developing countries. He stages a publicity stunt by flying in an Indian family and setting them up in a tent in the middle of London's St. James Park. But the prank backfires when it is discovered that one of them is suffering from malaria.

Doomwatch is alerted to a laboratory where a new toxic gas is being developed for military use, available in a 'handy' aerosol can for easy application during conflict. But Quist and Anne's enquiry soon leads them to doubt that the scientists' safety measures concerning the storage of the gas may not be as secure as they think.

Quist is concerned by the fact that, approximately every one hundred years, certain extreme weather conditions arise which lead to an increase in the water level of the Thames - and just one inch higher would result in the whole of London flooding. Even more disturbing is the fact that this increase is imminent.

When John Ridge's father, Wilfred, becomes seriously ill, he decides to devote all his time to looking after him. Wilfred is then taken to hospital and put into the care of Doctor Cordell, but shortly afterwards he dies. Ridge is suspicious, and his investigations uncover a disturbing fact: Doctor Cordell is an advocate of euthanasia.

Dolphins have long been established as highly-intelligent creatures, and the United States Navy has now begun using them in their new program. They are training the dolphins to act as underwater saboteurs, able to attach magnetic explosive devices to the undersides of enemy ships. Quist investigates the matter, and discovers that these apparently docile creatures are capable of becoming deadly killers - something that he experiences firsthand.

Astrophysics lecturer Neil Tannahill receives an enigmatic note from Dr. Spencer Quist, former head of Doomwatch, and finds himself drawn into a sinister conspiracy involving Soviet nuclear waste secretly stored at a British nuclear facility.