A military satellite returns to Earth. Aerial surveillance reveals that everyone in Piedmont, Arizona, the town closest to where the satellite landed, is apparently dead. The base commander suspects the satellite returned with an extraterrestrial organism and recommends activating Wildfire, a protocol for a government-sponsored team that counters extraterrestrial biological infestation.
The scientists believe the satellite, which was intentionally designed to capture upper-atmosphere microorganisms for bio-weapon exploitation, returned with a deadly microorganism that kills by nearly instantaneous disseminated intravascular coagulation (lethal blood clotting). Upon investigating the town, the Wildfire team discovers that the residents either died in mid-stride or went "quietly nuts" and committed bizarre suicides. Two Piedmont inhabitants—the sick, Sterno-addicted, geriatric Peter Jackson and the constantly bawling infant Jamie Ritter—are biological opposites who somehow survived the organism.
Jackson, the infant, and the satellite are taken to the secret underground Wildfire laboratory, a secure facility equipped with every known capacity for protection against a biological element escaping into the atmosphere, including a nuclear weapon to incinerate the facility if necessary. Wildfire is hidden in a remote area near the fictional town of Flatrock, Nevada, sixty miles from Las Vegas, concealed in the sub-basements of a legitimate Department of Agriculture research station. Dr. Hall is the only scientist authorized to disarm the automatic self-destruct mechanism; he is an unmarried male and thus presumed to make the most dispassionate decisions during crises.
Further investigation determines that the bizarre deaths were caused by a crystal-structured, extraterrestrial microbe transported by a meteor that crashed into the satellite, knocking it from orbit. The microbe contains chemical elements required for terrestrial life and appears to have a crystalline structure, but lacks DNA, RNA, proteins, and amino acids, yet it directly transforms matter to energy and vice versa.
The microbe, code named "Andromeda", mutates with each growth cycle, changing its biological properties. The scientists learn that Andromeda grows only within a narrow pH range; in a too-acidic or too-alkaline growth medium, it will not multiply. Andromeda's ideal pH range is 7.39–7.43, within the range found in normal human blood. That is why Jackson and Ritter survived: both had abnormal blood pH (Jackson acidotic from consumption of Sterno and Aspirin, the infant alkalotic from hyperventilation). However, by the time the scientists realize this, Andromeda has mutated into a form that degrades the lab's plastic shields and escapes its containment. Trapped in the contaminated laboratory, Dr. Burton demands that Stone inject him with Kalocin (a fictional "universal antibiotic"); Stone refuses, arguing it would render Burton too vulnerable to infection by other harmful bacteria. Burton survives because the mutated Andromeda is no longer lethal to humans.
The mutated Andromeda attacks the synthetic rubber door and hatch seals within the Wildfire complex, racing toward the upper levels and the surface. The self-destruct atomic bomb is automatically armed when it detects a containment breach, triggering its detonation countdown to prevent the spread of the infection. As the bomb arms, the scientists realize that given Andromeda's ability to generate matter directly from energy, the organism would be able to consume the released energy and ultimately benefit from an atomic explosion, growing into a super-colony within a day.
To halt the detonation, Dr. Hall must insert a special key he carries into an emergency substation anywhere in Wildfire. Unfortunately, he is trapped in a section with no substation. He must navigate Wildfire's obstacle course of automatic defenses to reach a working substation on an upper level. He barely disarms the bomb in time before all the air is evacuated from the deepest level of the Wildfire complex. Andromeda is suspected to have eventually mutated into a benign form and migrated to the upper atmosphere, where the oxygen content is lower, better suiting its growth.
The novel's epilogue reveals that a manned spacecraft, Andros V, was incinerated during atmospheric re-entry, presumably because Andromeda had eaten its plastic heat shield and caused it to burn up.Dr. Jeremy Stone – Professor and chair of the bacteriology department at Stanford University; Stone is fictitiously the winner of the 1961 Nobel Prize in Physiology or Medicine, whereas the actual winner was Georg von Békésy.
Dr. Charles Burton – Professor of pathology at the Baylor College of Medicine
Dr. Peter Leavitt – Clinical microbiologist; suffers from epilepsy
Dr. Mark Hall – Surgeon
Crichton was inspired to write the novel after reading The Ipcress File by Len Deighton while studying in England. Crichton says he was "terrifically impressed" by the book - "a lot of Andromeda is traceable to Ipcress in terms of trying to create an imaginary world using recogniseable techniques and real people." He wrote the novel over three years.
The "Odd-Man Hypothesis" is a fictional hypothesis which states that unmarried men are better able to execute the best, most dispassionate decisions in crises—in this case, to disarm the nuclear weapon intended to prevent the escape of organisms from the laboratory in the event the auto-destruct sequence is initiated. In the novel, the Odd-Man explanation is a page in a RAND Corporation report of the results of test series wherein different people were to make command decisions in nuclear and biological wars and chemical crises.
Hall is briefed on the Hypothesis after his arrival at Wildfire. In the book, his copy of the briefing materials has the Hypothesis pages removed; in the film, he is criticized for failure to read the material ahead of time.
Dr. Hall is assumed to have the highest "command decision effectiveness index" among the Wildfire team; this is the reason why he is given a control key to the self-destruct mechanism. Hall initially derides this idea, saying he has no intention of committing suicide. Stone then admits that the Odd-Man Hypothesis was essentially a false document fabricated to justify handing over a nuclear weapon to private individuals, and reveals that the weapon could be automatically triggered in the event of a breach of containment, and Hall is the only man who can disarm it.
In 1971, The Andromeda Strain was the basis for the film of the same name directed by Robert Wise, and featuring Arthur Hill as Stone, James Olson as Hall, Kate Reid as Leavitt (changed to a female character, Ruth Leavitt), and David Wayne as Dutton (Burton in the novel).
In 2008, The Andromeda Strain was the basis for an eponymous miniseries executive-produced by Ridley and Tony Scott and Frank Darabont, and featuring Benjamin Bratt as Stone. Other characters' names and personalities were radically changed from the novel.Death metal band Nocturnus has a song called "Andromeda Strain" on their début album, The Key
Progressive metal band Shadow Gallery has a song titled "The Andromeda Strain" about genetically engineered biological weapons on Room V
Reviews for The Andromeda Strain were overwhelmingly positive, and the novel was an American bestseller, establishing Michael Crichton as a respected novelist and science-fiction writer.
The Pittsburgh Press said it was "Relentlessly suspenseful... A hair-raising experience."
Detroit Free Press called it "Hideously plausible suspense... [that] will glue you to your chair.'
Library Journal said The Andromeda Strain was "One of the most important novels of the year (1969)."
The New York Times's Christopher Lehmann-Haupt said "Tired out by a long day in the country, I was awake way past bedtime. My arms were numb from propping up my head. By turning from side to side, I had driven the cats from their place at the foot of the bed, and they were disgruntled. I was very likely disturbing my wife's sleep. But I was well into Michael Crichton's The Andromeda Strain. And he had me convinced it was all really happening."